jeep grand cherokee wj_14a-3.1 td- sistema inyección

8/9/2019 Jeep Grand Cherokee Wj_14a-3.1 Td- Sistema Inyeccin

1/38

FUEL SYSTEM3.1L DIESEL ENGINE

TABLE OF CONTENTS

page page

GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1FUEL DELIVERY SYSTEM 3.1L DIESEL

ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

FUEL INJECTION SYSTEM 3.1L DIESELENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

GENERAL INFORMATION

TABLE OF CONTENTS

page page

DESCRIPTION AND OPERATIONFUEL REQUIREMENTS3.1L DIESEL . . . . . . . . 1

FUEL SHUTDOWN SOLENOID . . . . . . . . . . . . . . . 1

DESCRIPTION AND OPERATION

FUEL SHUTDOWN SOLENOID

DESCRIPTIONThe fuel shutdown solenoid is controlled and

operated by the ECM.The fuel shutdown (shut-off) solenoid is used to

electrically shut off t he diesel fuel supply to t he high-pr es su re f uel i nject i on p um p. Th e s ol en oi d i smounted to the rear of the injection pump.

The solenoid controls starting and stopping of theengine regardless of the posi t ion of the accelera tor

pedal . When the ignit ion (key) switch is OFF, thesolenoid is shut off and fuel flow is not allowed to thefuel in ject ion pump. When the key is p laced in theON or START positions, fuel supply is allowed a t theinjection pump.

FUEL REQUIREMENTS 3.1L DIESEL

DESCRIPTIONPremium qual i ty diesel fuel wi th a minimum Cet-

ane ra t ing of 50 or h igher is required.

WJ FUEL SYSTEM 3.1L DIESEL ENGINE 14 -


2/38


3/38

FUEL TANK MODULE

DESCRIPTIONAn elect r ic fuel pump is not a t tached to the fuel

t ank module for d ie se l powered eng ines . Fuel i s

drawn by the fuel injection pump.The fuel ta nk module is ins ta l led in the t op of t he

fuel tank. The fuel tank module contains the follow-ing components:

Fuel reservoir Electric fuel gauge sending unit Fuel supply line connection Fuel return line connection Wire harness Fuel inlet fi l ter (Strainer)

FUEL GAUGE SENDING UNIT

DESCRIPTIONThe fuel gauge sending uni t i s a t ta ched to t he s ide

of the fuel pump module. The sending unit consists ofa f loat , an arm, and a var iable resis tor ( t rack). Thetrack is used to send an electrical signal used for fuelgauge operation.

As the fuel level increases, the float and arm moveup. This decreases the sending unit resistance, caus-ing the P CM to send a s ignal t o the fuel gauge on thei ns t r um en t pa n el t o r ea d f ul l. As t h e f uel l ev eld ecr ea s es , t h e f loa t a n d a r m m ov e d ow n . Th is

increases the send ing un it r es is t ance , caus ing theP CM to send a s ignal to the fuel gauge on the ins t ru-ment panel to m ove towa rd empty.

FUEL FILTER/WATER SEPARATORThe fuel f i lter /wa ter separa tor i s located in the

engine compartment on the left side behind the gen-erator (Fig. 2).

The combinat ion fuel f i lter /wa ter separa tor pro-tects the fuel in ject ion pump by helping to removewater and contaminants f rom the fuel . Mois ture col-lects at the bottom of the fi l ter/separa tor in a plasticbowl.

The fuel fi l ter/wa ter separa tor assembly conta insthe fue l f il t er, fue l hea te r e lement , and fuel d ra in

valve.For informat ion on the fuel heater, refer t o FuelHeater in th is group.

Refer to the maintenance schedules in Group 0 inthis manual for the recommended fuel fi l ter replace-ment in tervals .

For periodic draining of water from the bowl, referto Fuel Filter/Wat er Separa tor Removal/Insta llationin this group.

Fig. 1 Typical Fuel Pressure Test at Injection Pump 1 FITTING2 HIGH PRESSURE LINE3 CARDBOARD

Fig. 2 Fuel Filter/Water Separator Location 1 FUEL FILTER/WATER SEPARATOR2 FUEL FILTER/WATER SEPARATOR RETAINING NUTS3 FUEL INLET HOSE4 ELECTRICAL CONNECTORS5 FUEL OUTLET HOSE


DESCRIPTION AND OPERATION (Continued)


4/38

FUEL SHUTDOWN SOLENOID

DESCRIPTIONThe fuel shutdown solenoid is controlled and

operated by the ECM.The fuel shutdown (shut-off) solenoid is used to

electrically shut off t he diesel fuel supply to t he high-pr es su re f uel i nject i on p um p. Th e s ol en oi d i smounted to the rear of the injection pump.

The solenoid controls starting and stopping of theengine regardless of the posi t ion of the accelera torpedal . When the ignit ion (key) switch is OFF, thesolenoid is shut off and fuel flow is not allowed to thefuel in ject ion pump. When t he key is p laced in theON or START positions, fuel supply is a llowed at theinjection pump.

FUEL INJECTION PUMPThe fuel injection pump is a mecha nical distr ibu-

tortype, Bosch VP36 ser ies (Fig . 3). A gear on theen d of t h e i nject i on pu m p s h a ft m es h es w i t h t h ed riv e g ea r a t t h e fr on t of en gin e. Th e pu mp ism ech a n ica l ly t i med t o t h e en gi ne. Th e E C M ca nm a k e a d ju st m en t s t o t h e t im in g of t h e i nject i onpump.

The inject ion pump conta ins the fuel shutdownsolenoid, fuel temperature sensor, control sleeve sen-sor, fuel quant i ty actuator and the fuel t iming sole-noid (Fig. 3).

In the electronically controlled injection pump, thepump plunger works the same as the pump plungerin a mechanically controlled injection pump, but theamount of fue l and the t ime the fue l i s in jected i s

con t rol led by the veh icles ECM, inst ead of by amechan ical governor a ssembly. A solenoid cont rolledby the ECM is used in place of the mechanical gov-ernor a ssembly, a nd it m oves a control sleeve insidethe pump tha t r egu la te s the amount of fue l beinginjected. There is no mecha nical connection between

the accelerator pedal an d the electronically controlledinject ion pump. Ins tead, a sensor connected to theaccelera tor pedal sends a s ignal to the E CM t hat rep-resents the actual posi t ion of the accelera tor pedal .Th e E C M u ses t h is i np ut , a l on g w i t h i np ut f romother sensors to move the control s leeve to del iverthe a ppropriate a mount of fuel. This syst em is knownas Dr ive-B y-Wire

The actual t ime that the fuel i s del ivered is veryimportant to the diesel combustion process. The ECMmonitors outputs from the engine speed sensor (fly-wheel position in degrees), and the fuel injector sen-sor (mechanical movement wi thin the #1 cyl inder

fuel in jector). Outputs f rom the Accelera tor P edalP osi t ion sensor, engine speed sensor (engine rpm)and engine coolant temperature sensor are also used.The ECM wil l then compare i t s se t values to theseoutputs to electrically adjust the amount of fuel t im-ing (amount of advance) wi thin the in ject ion pump.This is referred to as Closed Loop opera tion. TheECM monitors fuel t iming by comparing its set valueto when the injector #1 opens. If the value is greaterthan a p reset va lue a f au lt w i l l be se t .

Actual e lect r ic fuel t iming (amount of advance) isaccomplished by the fuel t iming solenoid mounted tothe bottom of the injection pump (Fig. 3). Fuel timingwil l be a djusted by the E CM, w hich controls the fueltiming solenoid.

An overf low valve is a t tached into the fuel re turnl ine a t the rear of the fuel in ject ion pump (Fig . 3).This va lve serves t wo purposes. One is to ensure th ata cer ta in amount of res idual pressure is mainta inedwi th in the pump when the eng ine i s swi tched off.This wi l l prevent the fuel t iming mechanism withinthe in ject ion pump from returning to i t s zero posi -t ion. The other purpose is to allow excess fuel to beretu rned to t he fuel t ank th rough the fue l r e tu rnline. The pressure values w ithin t his va lve are presetand can not be adjusted.

The fuel in ject ion pump supplies highpressurefuel of a pproximat ely 45,000 kP a (6526 psi) to ea chinjector in precise metered amounts a t the correcttime.

For mechan ica l in ject ion pump t iming , r efer toFuel I nject ion P ump Timing in the Service P roce-dures section of this group.

Fig. 3 Fuel Injection Pump 1 FUEL INJECTION PUMP ASSEMBLY

14 - 4 FUEL SYSTEM 3.1L DIESEL ENGINE WJ



5/38

FUEL INJECTORSFuel dra in tubes (Fig . 4) are used to route excess

f uel b a ck t o t h e o ver fl ow v a lv e a t t h e r e a r of t h einjection pump. This excess fuel is then returned tothe fuel tank through the fuel re turn l ine .

The injectors are connected to the fuel in ject ionpump by the h igh p ressu re fuel l ines . A sepa ra tein jector i s used for each of the f ive cy l inder s . Aninjector conta ining a sensor (Fig . 5) i s used on thecylinder number one injector. This injector is calledinstrumented injector #1 or needle movement sensor.I t i s u sed t o t el l t h e E C M w h en t h e # 1 i n ject or sin terna l spr ing-loaded va lve sea t has been forcedopen by pressurized fuel being delivered t o the cylin-der, which is a t the end of i t s compress ion s t roke.When the instrumented injector s valve seat is forceopen , i t s en d s a s m a ll v ol t a ge s pi ke pu ls e t o t h eECM. This tells the ECM that cylinder #1 is firing. It

is not used with the other four injectors.Fuel ente rs the in jector a t t he fuel in le t (top ofinjector) and is routed to the needle valve bore. Whenfuel pressure rises to approximat ely 15,00015,800kPa (21752291 psi), the needle valve spring tensionis overcome. The needle va lve r ises and fuel f lowsth rough the spray holes in the nozz le t ip in to thecombust ion chamber. The pressure required to l i ftthe needle valve is the injector opening pressure set-t ing. This is referred to a s the pop-off pressure set-t ing.

Fuel pressure in the injector circuit decreases aft erinjection. The injector needle valve is immediatelyclosed by the needle valve spr ing and fuel f low intothe combust ion chamber is s topped. Exhaust gasesare prevented f rom enter ing the in jector nozzle bythe needle valve.

A copper washer (gasket ) i s used a t the base o f

each injector (Fig . 5) to prevent combust ion gasesfrom escaping.Fuel injector firing sequence is 12453.

FUEL TUBES/LINES/HOSES AND CLAMPSLOW-PRESSURE TYPE

DESCRIPTIONAlso refer to the proceeding section on QuickCon-

nect Fitt ings.Inspect a l l hose connect ions such as c lamps, cou-

pl ings and f i t t ings to make sure they are secure andleaks a re not p resen t . The componen t shou ld bereplaced immediately if there is any evidence of deg-radat ion that could resul t in fa i lure .

Never at tempt to repair a plastic fuel l ine/tube or aquickconnect fitt ing. Replace complete line/tube a snecessary.

Avoid conta ct of a ny fuel t ubes/hoses with othervehicle components that could cause abra s ions orscuffing. B e sure t hat the fuel l ines /tubes are prop-e rly rou ted to p revent p inch ing and to avoid hea tsources.

Fig. 4 Fuel Injectors and Drain Tubes 1 FUEL DRAIN TUBES2 FUEL INJECTORS3 FITTING AT PUMP

Fig. 5 Fuel Injector Sensor 1 NEEDLE MOVEMENT SENSOR2 FUEL INJECTOR (NUMBER 1 CYLINDER ONLY)3 COPPER WASHER4 SENSOR CONNECTOR




6/38

The lines/tubes/hoses a re of a special const ruction.If i t is necessary to replace these l ines/tubes/hoses,use only original equipment type.

The hose c lamps used to secure the rubber hosesare of a specia l rol led edge construct ion. This con-s t ruct ion i s used to p reven t the edge o f the cl amp

from cut t ing in to the hose. Only t hese rol led edgetype cl amps may be used in th i s sys tem. All othertypes o f c lamps may cu t in to the hoses and causefuel leaks.

Wh er e a r ub ber h os e i s joi ned t o a m et a l t u be(s t aked), do not a t t empt to r epa ir. Rep lace ent i r eline/tu be a ssem bly.

Use new or igina l equipment type hose cl amps .Tighten hose clam ps t o 2 Nm (20 in. lbs.) torque.

QUICK-CONNECT FITTINGS LOW PRESSURETYPE

DESCRIPTIONDifferent types of quick-connect fi t t ings ar e used t o

attach various fuel system components. These are: as ingle-ta b type, a two-tab type or a p las t ic re ta inerring type (Fig. 6). Refer to Quick-Connect Fitt ings inthe Removal /Ins ta l la t ion sect ion for more informa-tion.

CAUTION: The interior components (o-rings, spac-ers) of quick-connect fitting are not serviced sepa-rately, but new pull tabs are available for sometypes. Do not attempt to repair damaged fittings orfuel lines/tubes. If repair is necessary, replace thecomplete fuel tube assembly.

HIGH-PRESSURE FUEL LINES

DESCRIPTION

CAUTION: The highpressure fuel lines must beheld securely in place in their holders. The linescannot contact each other or other components. Donot attempt to weld highpressure fuel lines or torepair lines that are damaged. Only use the recom-mended lines when replacement of highpressurefuel line is necessary.

Highpressure fuel l ines del iver fuel under pres-sure of up to approximat ely 45,000 kPa (6526 P SI)from the in ject ion pump to the fuel in jectors. Thel ines expand and con t rac t f rom the h ighpressu refuel pulses generated during the injection process. Allhighpressure fuel l ines are of the same length andinside d iamete r. Cor rect h ighpressure fuel l ineusage a nd inst a l l a t ion i s cr i t ica l to smooth eng ineoperation.

WARNING: USE EXTREME CAUTION WHENINSPECTING FOR HIGHPRESSURE FUEL LEAKS.INSPECT FOR HIGHPRESSURE FUEL LEAKS WITHA SHEET OF CARDBOARD. HIGH FUEL INJECTIONPRESSURE CAN CAUSE PERSONAL INJURY IFCONTACT IS MADE WITH THE SKIN.

FUEL DRAIN TUBESThese rubber tubes are lowpressure type.Some excess fuel i s cont inual ly vented f rom the

fuel injection pump. During injection, a sma ll a mountof f uel f low s pa s t t h e i nject or n oz zl e a n d i s n otin jected in to the combus t ion chamber. Th i s fueldrains in to the fuel dra in tubes (Fig . 7) and back tothe tee banjo f i t t ing, which is connected to the samel ine a s the over f low va lve , wh ich a l lows a va r i ab lequan t i ty to r etu rn to the fuel t ank . The over f low v a lv e i s ca l ib ra t e d t o open a t a pr es et pr es su re.Excess fuel not required by the pump to maintain themin imum pump cav i ty p ressure i s then retu rnedth rough the over f low va lve a nd on to the fue l t ankthrough the fuel re turn l ine .

Fig. 6 Plastic Retainer Ring-Type Fitting 1 FUEL TUBE2 QUICK CONNECT FITTING3 PUSH4 PLASTIC RETAINER5 PUSH6 PUSH7 PUSH8 PUSH




7/38

FUEL HEATER

DESCRIPTIONThe fuel heater is used to prevent diesel fuel from

w a x in g a n d pl ug gi ng t h e f uel f il t er d ur in g col dweather operat ion. The fuel heater i s located in the

bottom plastic bowl of the fuel fi l ter/wa ter separ at or(Fig. 8).

The element inside the heater assembly is made ofa P ositive Tempera ture Coefficient (P TC) m at erial ,and has power appl ied to i t by the fuel heater re layanytime the ignition key is in the on position. PTCmater ia l has a high res is tance to current f low wheni ts temperature is h igh, which means that i t wi l l notgenerate heat when the temperature is above a cer-ta in value . When the temperature is below 7C (45F), the resistance of the PTC element is lowered, anda l lows cur ren t to f low th rough the fuel hea te r e le -men t warming the fuel . When the t empera tu re i sabove 29C (85 F ), t he PTC e lement s r es i st ancer ises , a nd current f low through the heat er e lementstops.

Voltage to operate the fuel heater is supplied fromthe ignition (key) switch and through the fuel heaterre lay. Refer to the fol lowing Fuel Heat er Relay foraddi t ional informat ion. The fuel heater and fuelheater relay are not controlled by the Power-train Control Module (ECM).

FUEL HEATER RELAY

DESCRIPTIONVoltage to operate the fuel heater is supplied from

the ign i t ion (key) swi tch th rough the fue l hea te rrelay. The PCM or ECM is not used to controlthis relay.

The fue l hea te r r e l ay i s loca ted in the PDC. TheP DC is locat ed next to the ba t tery in the engine com-par tmen t . For the loca t ion of the r el ay wi th in thePDC, refer to label on PDC cover.

DIAGNOSIS AND TESTING

GENERAL INFORM ATIONThis section of the group will cover a general diag-

nosis of diesel engine fuel system components.Diagnostic Trouble Codes: Refer to On-Board

Diagnost ics in Group 25, Emiss ion Control System

for a list of Dia gnostic Trouble Codes (DTCs) for cer-tain fuel system components.

VISUAL INSPECTIONA visual inspection for loose, disconnected, or in cor-

rectly routed wires and hoses should be made beforea t t empt ing to d iagnose or serv ice the d iese l fue linjection system. A visual check will help find thesecondi t ions . I t a lso saves unnecessary tes t a nd diag-nostic t ime. A thorough visual inspection of the fuelinjection system includes the following checks:

Fig. 7 Fuel Drain Tubes 1 FUEL DRAIN TUBES2 FUEL INJECTORS3 FITTING AT PUMP

Fig. 8 Fuel Heater Temperature Sensor and Element Location

1 TERMINAL 22 FUEL HEATER3 TERMINAL 1




8/38

(1) Be sure that the bat tery connect ions are t ightand not corroded.

(2) B e s ur e t h a t t h e 60 w a y con n ect or i s f ul lyengaged wi th the P CM.

(3) B e s ur e t h a t t h e 68 w a y con n ect or i s f ul lyengaged wi th the ECM.

(4) Ver ify tha t the e lect r ical connect ions for theASD relay are clean and free of corrosion. This relayi s loca ted in the PDC. For the loca t ion o f the r e l aywithin the PDC, refer to label on PDC cover.

(5) Ver ify tha t the e lect r ical connect ions for thefuel heater relay are clean an d free of corrosion. Thisre l ay i s loca ted in the PDC. For the loca t ion o f therelay wi thin the PDC, refer to label on PDC cover.

(6) Be sure the electrical connectors at the ends ofthe glow plugs (Fig. 9) are t ight an d free of corrosion.

(7) Be sure tha t the e lect r ical connect ions a t theglow plug relay are t ight and not corroded. The glow plug re lay is located in the engine compartment onthe leftinner fender (Fig. 10) (Fig. 11).

(8) Inspect t he s ta r ter motor a nd s tar ter solenoidconnections for t ightness and corrosion.

(9) Ver ify tha t the Fuel Inject ion P ump elect r icalconnector is firmly connected. Inspect the connectorfor corrosion or damaged wires.

(10) Verify that the fuel heater electrical connectoris f i rmly a t tached to the f i l ter bowl a t the bot tom ofthe fuel fi l ter/wa ter separ at or. Inspect the connectorfor corrosion or damaged wires.

(11) Ver ify that the e lect r ical p igta i l connector(sensor connector) (Fig. 12) for the fuel injector sen-sor is firmly connected to the engine wiring harness.Inspect the connector for corrosion or damaged wires.This sensor is used on the #1 cylinder injector only.

(12) I nspect for exhaust sys tem res t r ic t ions suchas pinched exhaust p ipes or a col lapsed or p luggedmuffler.

(13) Veri fy tu rbocharger was tega te opera t ion .R ef er t o G r ou p 11, E x ha u s t S y s t em a n d Tu r bo-charger Group for information.

(14) Ver ify that the harness connector is f i rmlyconnected to t he engine coolan t temperature sensors.The (PCM) E . C. T. sensor is located on the s ide of

cyl inder head near the rear of fuel in ject ion pump(Fig. 13). The (ECM) E . C . T. sens or is locat ed on t hes ide of the cyl inder head jus t to the rear of the PCMsensor (Fig. 13).

(15) C heck for a i r in t he fuel sys tem. Refer to theAir Bleed Procedure.

(16) Inspect a l l fuel supply and re turn l ines forsigns of leakage.

(17) Be sure tha t the ground connect ions are t ightand f ree of corrosion. Refer to Group 8 , Wir ing forlocations of ground connections.

Fig. 9 Glow Plug Connector 1 GLOW PLUG ELECTRICAL CONNECTOR

CAV COLOR FUNCTION

30 RD/DB FUSED B(+)

85 DB/ WT

FUSED ASD RELAYOUTPUT

86 WT GLOW PLUG RELAY#1 CONTROL

87 GY GLOW PLUG RELAY#1 OUTPUT

Fig. 10 Glow Plug Relay #1 Location

CAV COLOR FUNCTION

30 VT/ RD FUSED B(+)

85 DB/ WT

FUSED ASD RELAYOUTPUT

86 LB/WT GLOW PLUG RELAY#2 CONTROL

87 GY/YL GLOW PLUG RELAY#2 OUTPUT



DIAGNOSIS AND TESTING (Continued)


9/38

(18) Inspect the a i r cleaner e lement (f i lter ) forrestrictions.

(19) Be sure that the turbocharger output hose isproper ly connected to the charge a i r cooler (in ter-cooler) in le t tube. Ver ify that the charge a i r cooleroutput h ose is properly connected to t he cooler a nd

the intake manifold. Refer to Group 11, Exhaust Sys-tem an d Turbocharger for informa tion.

(20) Be sure that the vacuum hoses t o the vacuumpump are connected and not leaking. The va cuumpump is located in the front of engine (internal) andis driven from the crankshaft gear (Fig. 14). Discon-

nect the hose and check for minimum vacuum fromthe pump. Refer to Group 5 , Brake System for spec-ifications an d procedures.

(21) B e su re tha t the accessory d r ive bel t i s notdamaged or slipping.

(22) Verify there is a good connection at the enginespeed sensor. Refer to the Fuel Inject ion System inthis sect ion for locat ion of the engine speed sensor

location.(23) Verify there is a good connection at the BoostP r e ss ur e S e n sor, w h ich i s a pa r t of t h e a i r i nt a k eassembly.

AIR IN FUEL SYSTEMAir wi l l enter t he fuel sys tem whenever t he fuel

supply l ines , fuel f i lter /wa ter separa tor, fuel f i lterbowl, injection pump, highpressure lines or injectorsare removed or disconnected. Air will also enter thef uel s y st em w h en ev er t h e f uel t a n k h a s b een r u nempty.


Fig. 13 Engine Coolant Temperature Sensor

Locations 1 PCM ENGINE COOLANT TEMPERATURE (ECT) SENSOR2 ECM ENGINE COOLANT TEMPERATURE (ECT) SENSOR3 ECM ECT SENSOR HARNESS CONNECTOR4 PCM ECT SENSOR HARNESS CONNECTOR

Fig. 14 Vacuum Pump at Front of Engine 1 VACUUM PUMP2 CAMSHAFT3 INJECTION PUMP4 TIMING MARKS5 OIL PUMP6 CRANKSHAFT




10/38

Air t rapped in the fuel sys tem can resul t in hardstarting, a rough running engine, engine misfire, low power, excessive smoke and fuel knock. After servicei s per for m ed , a i r m u st b e b led f rom t h e s y st embefore starting the engine.

Inspec t the fue l sys tem f rom the fue l t ank to the

injectors for loose connect ions . Leaking fuel i s anindicat or of loose connections or defective sea ls. Aircan a lso enter the fuel sys tem between the fuel tankand the in ject ion pump. Inspect the fue l t a nk andfue l l ines fo r damage tha t migh t a l low a i r in to thesystem.

For a i r b leeding, refer to Air Bleed P rocedure inthe Service Procedures section of this group.

FUEL HEATER RELAY TESTThe fuel heater re lay is located in the Power Dis-

tribution Center (PDC). Refer to RelaysOperation/Test ing in Fuel Ingect ion Sys tem sect ion of th i s

group for test procedures.

FUEL INJECTOR TESTThe fuel in ject ion nozzels , located in the engine

cyl inder head, spray fuel under high pressure in tothe individua l combus t ion chambers . P ressu r izedfuel, delivered by the fuel injection pump, unseats aspr ing-loaded needle valve ins ide the in jector, andthe fuel is a tomized a s i t escapes th rough the injectoropening into the engines combustion chamber. If thefuel in jector does not operate proper ly, the enginemay misfire, or cause other driveabili ty problems.

A leak in the injection pumptoinjector highpres-sure fuel l ine can cause ma ny of the same symptomsas a malfunctioning injector. Inspect for a leak in thehighpressure l ines before checking for a malfunc-tioning fuel injector.

WARNING: THE INJECTION PUMP SUPPLIES HIGH- PRESSURE FUEL OF UP TO APPROXIMATELY45,000 KPA (6526 PSI) TO EACH INDIVIDUAL INJEC-TOR THROUGH THE HIGHPRESSURE LINES. FUELUNDER THIS AMOUNT OF PRESSURE CAN PENE-TRATE THE SKIN AND CAUSE PERSONAL INJURY.WEAR SAFETY GOGGLES AND ADEQUATE PRO-TECTIVE CLOTHING. AVOID CONTACT WITH FUELSPRAY WHEN BLEEDING HIGHPRESSURE FUELLINES.

WARNING: DO NOT BLEED AIR FROM THE FUELSYSTEM OF A HOT ENGINE. DO NOT ALLOW FUELTO SPRAY ONTO THE EXHAUST MANIFOLD WHENBLEEDING AIR FROM THE FUEL SYSTEM.

To determine w hich fuel injector is ma lfunctioning,run the engine a nd loosen the h ighpressure fuel l inenut a t the in jector (Fig . 15). Lis ten for a change in

engine speed. If engine speed drops, the injector wasopera t ing normal ly. I f eng ine speed remains thesame, the injector may be malfunctioning. After test-i ng , t i gh t en t h e l in e n u t t o 19 N m (14 f t . l bs .)torque. Test a ll injectors in t he sa me ma nner one ata t ime.

Once an injector has been found to be malfunction-ing, remove i t f rom the engine and tes t i t . Refer tothe R emoval/Ins ta llat ion section of this group for pro-cedures.

After the injector has been removed, install i t to abenchmount in jector t e st e r. Refer to opera t inginstructions supplied with tester for procedures.

The opening pressure or pop pressure should be15,00015,800 kP a (21752291 psi). If th e fuel injec-tor needle valve is opening (popping) to early or tolate, replace the injector.

FUEL INJECTOR / NEEDLE MOVEMENTSENSOR TEST

The needle movement sensor is used only on thenumber1 cyl inder fuel in jector (Fig . 16). I t i s notused on the injectors for cylinders number 2, 3, 4 or5.

Testing the needle movement sensor requires theu se of a D R B S ca n t ool . R e fer t o t h e P o w er t ra i nDiagnost ic P rocedures manua l for addi t ional infor-mat ion.

Fig. 15 Typical Inspection of Fuel Injector 1 FUEL INJECTOR2 LINE FITTING3 HIGH-PRESSURE FUEL LINE4 FUEL DRAIN TUBES




11/38

FUEL INJECTION PUMP TESTThe injection pump is not to be serviced or

the warranty may be voided. If the injectionpump requires service, the complete assemblymust be replaced.

Incorrect in ject ion pump t iming (mechanical ore lect r ical ) can cause poor performance, excessive

smoke and emissions and poor fuel economy.A defective fuel injection pump, defective fuel tim-

ing solenoid or misadjusted mechanical pump timingcan cause s t a r t ing p rob lems or p reven t the eng inefrom revving up. I t can a lso cause:

Engine surge a t id le Rough idle (warm engine) Low power Excessive fuel consumption Poor performance Low power B lack smoke f rom the exhaust B lue or whi te fog l ike exhaust Incorrect idle or maximum speedThe e lect ronical ly controlled fuel pump has no

mechanical governor l ike older mechanical ly con-t rolled fuel pumps. Do not remove t he top cover ofthe fuel pump, or the screws fas t en ing the wi r ingp ig ta i l t o the s ide o f the pump. The warranty of the injection pump and the engine may be voidif those seals have been removed or tamperedwith.

FUEL SUPPLY RESTRICTIONS

LOWPRESSURE LINESRestricted or P lugged supply lines or fuel fi l ter can

cause a t iming faul t tha t wi l l cause the E CM t o oper-a t e t h e e n gi ne i n a L im p H om e m od e. S e e t h e

in t roduct ion of the Fuel In ject ion Sys tem in th i sgroup for more informa tion on t he Limp Home mode.Fuel supply line restrictions can cause starting prob-lems and prevent the engine f rom revving up. Thes ta r t ing p rob lems include; low power and b lue orwh ite fog like exhaust. Test all fuel supply lines forres t r ic t ions or b lockage. Flush or replace a s neces-sary. Bleed the fuel sys tem of a i r once a fuel supplyline has been replaced. Refer to the Air Bleed Proce-dure section of this group for procedures.

HIGHPRESSURE LINESRestricted (kinked or bent) highpressure lines can

cause s tar t ing problems, poor engine performanceand black smoke f rom exhaust .

Examine a l l h ighpressure l ines for any dama ge.E a c h r a d iu s on ea c h h ig h p res su r e l in e m u st b esmooth and f ree of any bends or k inks .

Replace damaged, restricted or leaking highpres-sure fuel l ines with the correct replacement l ine.

CAUTION: The highpressure fuel lines must beclamped securely in place in the holders. The linescannot contact each other or other components. Donot attempt to weld highpressure fuel lines or torepair lines that are damaged. Only use the recom-mended lines when replacement of highpressurefuel line is necessary.

FUEL SHUTDOWN SOLENOID TESTRefer to the 3.1L Diesel Powert ra in Diagnos t i c

Manual for the Fuel Shutdown Solenoid tes t .

HIGH-PRESSURE FUEL LINE LEAK TESTHighpressure fuel l ine l eaks can cause s t a r t ing

problems an d poor engine performa nce.

WARNING: DUE TO EXTREME FUEL PRESSURESOF UP TO 45,000 KPA (6526 PSI), USE EXTREMECAUTION WHEN INSPECTING FOR HIGHPRES-SURE FUEL LEAKS. DO NOT GET YOUR HAND, ORANY PART OF YOUR BODY NEAR A SUSPECTEDLEAK. INSPECT FOR HIGHPRESSURE FUELLEAKS WITH A SHEET OF CARDBOARD. HIGHFUEL INJECTION PRESSURE CAN CAUSE PER-SONAL INJURY IF CONTACT IS MADE WITH THESKIN.

Fig. 16 Needle Movement Sensor Location 1 NEEDLE MOVEMENT SENSOR2 FUEL INJECTOR (NUMBER 1 CYLINDER ONLY)3 COPPER WASHER4 SENSOR CONNECTOR




12/38

S t a r t t h e en g in e. M ov e t h e ca r d boa r d ov er t h ehighpressure fuel l ines a nd check for fuel spray ontothe cardboard (Fig. 17). I f a highpressure l ine con-nect ion is leaking, b leed the system and t ighten theconnection. Refer to the Air Bleed Procedure in thisgroup for procedures. Replace damaged, restricted or

l eak ing h ighpressure fuel l ines wi th the cor rectreplacement line.

CAUTION: The highpressure fuel lines must beclamped securely in the holders. The lines cannotcontact each other or other components. Do notattempt to weld highpressure fuel lines or to repairlines that are damaged. Only use the recommendedlines when replacement of highpressure fuel lineis necessary.

SERVICE PROCEDURESAIR BLEED PROCEDURES

AIR BLEEDING AT FUEL FILTERA certain amount of air may become trapped in the

fuel sys tem w hen fuel sys tem components are ser-viced or replaced. Bleed the system as needed af terfuel system service according to the following proce-dures.


Some ai r enters the fuel sys tem when the fuel f i l -ter or in ject ion pump supply l ine is changed. Thissmal l amount of a i r i s vented automat ical ly f rom theinjection pump through the fuel drain manifold tubesi f t he f i l ter wa s changed according t o ins t ruct ions .Ensure the the fuel f il ter /wa ter separa tor i s fu ll offuel

I t may be necessary to manual ly bleed the systemif :

The bowl of the fuel fi l ter/wa ter separ at or is notpartially fi l led before installation of a new fil ter

The injection pump is replaced Highpressure fuel line connections are loosened

or lines replaced

I n it ia l en gi ne s t a rt u p or s ta r t u p a f ter a nextended period of no engine operat ion Running fuel tank empty

FUEL INJECTION PUMP BLEEDING(1) I f the fuel in ject ion pump ha s been replaced,

a i r s h ou ld b e b led a t t h e ov er fl ow v a lv e b ef or eat tempting to s tar t engine.

(a ) Loosen the over f low va lve (F ig. 18) a t t herear of the injection pump.

(b) Place a towel below the valve .Fig. 17 Typical Fuel Pressure Test at Injection Pump 1 FITTING

2 HIGH PRESSURE LINE3 CARDBOARD

Fig. 18 Overflow Valve 1 FUEL INJECTION PUMP ASSEMBLY2 FUEL RETURN LINE3 FUEL SUPPLY LINE4 FUEL INJECTION PUMP 10WAY CONNECTOR5 TIMING SOLENOID6 OVERFLOW VALVE




13/38

WARNING: WHEN CRANKING THE ENGINE TOBLEED AIR FROM THE INJECTION PUMP, THEENGINE MAY START. PLACE THE TRANSMISSIONIN NEUTRAL OR PARK AND SET PARKING BRAKEBEFORE ENGAGING THE STARTER MOTOR.

CAUTION: Do not engage the starter motor formore than 30 seconds at a time. Allow 2 minutesbetween cranking intervals.

(2) C rank the eng ine for 30 seconds a t a t ime toal low ai r t rapped in t he in ject ion pump to vent outthe fuel injector dra in t ubes. Continue this procedureuntil the engine sta rts. Observe t he previous WARN-ING and CAUTION.

(3) Tighten overflow valve.

HIGHPRESSURE FUEL LINE BLEEDING

WARNING: THE INJECTION PUMP SUPPLIES HIGH- PRESSURE FUEL OF APPROXIMATELY 45,000 KPA(6,526 PSI) TO EACH INDIVIDUAL INJECTORTHROUGH THE HIGHPRESSURE LINES. FUELUNDER THIS AMOUNT OF PRESSURE CAN PENE-TRATE THE SKIN AND CAUSE PERSONAL INJURY.WEAR SAFETY GOGGLES AND ADEQUATE PRO-TECTIVE CLOTHING AND AVOID CONTACT WITHFUEL SPRAY WHEN BLEEDING HIGHPRESSUREFUEL LINES.


Bleed air from one injector at t ime.(1) Loosen the highpressure fuel l ine f it t ing a t

the injector (Fig. 19).(2) Crank the eng ine un t i l a l l a i r ha s been b led

from the l ine . Do not operate the starter motorfor longer than 30 seconds. Wait 2 minutesbetween cranking intervals.

(3) S ta r t t he eng ine and b leed one in jector a t atime until the engine runs smoothly.

FUEL INJECTION PUMP TIMINGR ef er t o t h e F u el I n ject i on P u m p R em ov a l a n d

Installation procedure in Service Procedures later inthis Group.

REMOVAL AND INSTALLATION

AIR CLEANER ELEMENT

REMOVAL(1) Loosen 4 c lamps holding a i r cleaner housingha lves t ogether.

(2) Remove top of air cleaner housing.(3) Remove element from air cleaner housing.

INSTALLATION(1) Ins ta l l a new element in housing.(2) Position housing halves together.(3) Snap clamps into place.

FUEL DRAIN TUBESThe fuel dra in tubes (Fig . 20) a re lowpressure

type.P ul l each t ube f rom the in jector for removal . P ush

on for installation. Clamps are not required for thesetubes.

FUEL FILTER/WATER SEPARATORThe fuel f i lter /wa ter separa tor i s located in the

engine compartment on the left side behind the gen-erator (Fig. 21).

Fig. 19 Bleeding HighPressure Fuel LineTypical 1 FUEL INJECTOR2 LINE FITTING3 HIGH-PRESSURE FUEL LINE4 FUEL DRAIN TUBES


SERVICE PROCEDURES (Continued)


14/38

The fuel fi l ter/wa ter separa tor assembly conta insthe fue l f il t er, fue l hea te r e lement , and fuel d ra invalve.

DRAINING WATER FROM FILTER BOWLMoisture (wat er) collects at the bottom of the fi l ter/

separa tor in a plas t ic bowl . Water enter ing t he fueli nject i on pu m p ca n ca u s e s er iou s d a m a g e t o t h epump. Note that the bulb will be illuminated forapproximately 2 seconds each time the key isinitially placed in the ON position. This is donefor a bulb check.

WARNING: DO NOT ATTEMPT TO DRAIN WATERFROM THE FILTER/SEPARATOR WITH THE ENGINEHOT.

(1) The bot tom of the f il t er /sepa ra tor bowl i seq u ipp ed w i t h a d r a in v a lv e. Th e d r a in v a lv e i s

equipped with a fi t t ing. Attach a piece of rubber hoset o t h i s f it t i ng . Th is h os e i s t o b e u sed a s a d r a inhose.

(2) Place a dra in pan under the drain hose .(3) With the engine not running, open the drain

valve (unscrewdrain valve has r ight hand threads)from the fi l ter/separ at or bowl. To ga in access to thisf i t t ing, the two f i ltertomount ing bra cket nuts mayhave to be loosened a few turns .

(4) Hold the drain open unt i l c lean fuel exi ts thedrain .

(5) After draining, close drain valve.(6) Remove rubber drain hose.

(7) Dispose of mixture in drain pan according t oapplicable local or federal regulations.

FUEL FILTER REMOVAL(1) D ra in all fuel a nd/or wa ter from fuel fi l ter/wa -

ter separa tor a ssembly. Refer t o the previous Dra in-ing Wat er From Filter B owl.

(2) Unplug the e lect r ical connectors a t bot tom ofplastic bowl.

(3) Remove plastic bowl from bottom of fuel fi l ter(unscrews).

(4) Remove fuel f i lter f rom bot tom of f i lter base(unscrews).

FUEL FILTER INSTALLATION(1) Clean bottom of fuel fi l ter base.(2) Apply clean diesel fuel to new fuel filter gasket.(3) Insta ll an d t ighten fi l ter to fi l ter ba se. The bev-

e led pa r t of the rubber gasket shou ld be f ac ing uptowards the f i l ter base .

(4) Clean the ins ide of bowl w i th a soap a nd w atermixture before installation. Carefully clean any resi-due between the tw o meta l p robes a t the top o f thewa terinfuel sensor. Do not use chemical cleanersas damage to the p las t i c bowl may resu lt .

Fig. 20 Fuel Injectors and Drain Tubes 1 FUEL DRAIN TUBES2 FUEL INJECTORS3 FITTING AT PUMP

Fig. 21 Fuel Filter / Water Separator Position &Orientation

1 FUEL FILTER/WATER SEP. RETAINING NUTS2 FUEL PRIMING PUMP3 FUEL LINE FROM TANK4 FUEL FILTER5 FUEL LINE TO INJECTION PUMP6 FUEL FILTER/WATER SEPARATOR


REMOVAL AND INSTALLATION (Continued)


15/38

(5) P our d iesel fue l in to the p las t i c bowl beforeinsta ll ing bowl to bottom of fuel fi l ter. D o this to helpprevent air from entering fuel injection pump w hileat tempting to s tar t ing engine.

(6) Install f i l ter bowl to bottom of fi l ter.(7) Ins ta l l the e lect r ical connectors a t bot tom of

bowl.(8) Tighten the f i ltertomount ing bracket nuts(Fig. 21) to 28 Nm (250 in. lbs.) torque.

FUEL HEATERI f the fuel heater e lement needs replacement , the

plas t ic f i lter bowl assembly must be replaced. Referto Fuel Filter/Wat er Separa tor for informa tion.

FUEL HEATER RELAYThe fuel hea te r r el ay i s loca ted in the P DC. For

the loca t ion of the r e l ay wi th in the PD C (F ig. 22),refer to label on PDC cover.

FUEL LEVEL SENSORThe fuel level sensor is located on the s ide of the

fuel pump module.

REMOVAL(1) Remove fuel ta nk. Refer t o Fuel Tan k R emoval/

Ins ta l la t ion.(2) Remove fuel pump module. Refer to F uel P ump

Module Remova l/Ins ta llat ion(3) Remove e lect r ical wire connector a t sending

uni t terminals .(4) Press on re lease tab (Fig . 23) to remove level

sensor from the pump module.

FUEL INJECTION PUMP

REMOVAL(1) Disconnect the negative battery cable.(2) Remove the in take a i r duct r et a in ing bol t s

f rom the top of the in take manifold .(3) Disconnect the intercooler outlet hose from t he

intercooler.(4) Remove the eng ine in take a i r duct and hose

assembly from the vehicle.(5) Remove the engine accessory drive belt . Refer

to Group 7, Cooling System for the procedure.(6) Remove the generat or assembly. Refer to G roup

8C, Charging System for the procedure.(7) Th or ou gh ly t h e cl ea n t h e a r ea a r ou n d t h e

inject ion pump and fuel l ines of a l l d i r t , grease andother contaminants. Due to the close internal tol-erances of the injection pump, this step must beperformed before removing pump.

(8) Remove the rubber fue l r etu rn and supp lyhoses f rom the metal l ines a t the pump (Fig . 24).

(9) Disconnect the engine coolant temperature sen-sor electrical connector (Fig. 25). Locat ed closest tothe injection pump.

(10) Disconnect the Fuel Injection Pump electricalconnector at the pump. (Fig. 24).

(11) Disconnect the main engine wir ing harnessfrom the glow plugs.

CAV COLOR FUNCTION

30 RD/TN FUSED B(+)

85 OR IGNITION SWITCHOUTPUT

86 BK GROUND

87 RD/BK FUEL HEATERRELAY OUTPUT

Fig. 22 Power Distribution Center (PDC)

Fig. 23 Fuel Level Sensor Release Tab 1 ELECTRICAL CONNECTOR2 FUEL LEVEL SENSOR3 RELEASE TAB4 FUEL RESERVOIR MODULE




16/38

(12) Disconnect the five highpressure fuel l inesfrom the fuel in ject ion pump. Also disconnect fuell ines a t the fuel in jectors. For procedures , refer toHighPressure Fuel Lines in th is group. Place a ragbeneath the fi t t ings to catch excess fuel.

(13) Remove the plug from timing gear cover.(14) The Top D ead Cent er (T. D. C.) compression

firing position for the #1 cylinder can be determinedas follows:

(a ) U s ing a socket a t t a ched to the f ron t of thecrankshaf t , ro ta te the engine c lockwise unt i l spe-cia l a l ignment tool VM# 8374 can be inser t edthrough the T. D. C. tool access hole in the r ights ide of the t r ansmiss ion adap ter p la t e (F ig. 26),stopping the flexplat e rotat ion. This position is T.D. C. or 360 (crankshaf t deg.) awa y from T. D . C.Engine must be positioned at T. D. C. on #1cylinder compression firing stroke.

(b) To verify th at you ar e a t T. D. C. Remove theoi l f i ll cap f rom the cy linde r head cover and theal ignment tool f rom the t ra nsmiss ion ada pter p la t e .

(c) R ot a t e t h e cr a n ks h a ft on e-q u a r t er t u rncounter-clockwise an d clockwise while observingthe cyl inder #2 in take rocker arm through the oi lfi l l cap hole. (The intake valve rocker arm shouldstop moving). If the rocker arm does not move youha ve identified T. D . C .

(d) If T. D . C . w as found continue t he procedure,i f not rota te the crankshaf t one revolut ion (360)unt i l the a l ignment tool can be re- ins ta l led in theflexplat e (Fig. 26). T. D . C . is now identified for t he#1 cyl inder compress ion f i ring s t roke. Mark thedam per an d timing cover for quick reference t o T.

Fig. 24 Fuel Injection Pump 1 FUEL INJECTION PUMP ASSEMBLY2 FUEL RETURN LINE3 FUEL SUPPLY LINE4 FUEL INJECTION PUMP 10WAY CONNECTOR5 FUEL TIMING SOLENOID

Fig. 25 Engine Coolant Temperature Sensors 1 PCM ENGINE COOLANT TEMPERATURE (ECT) SENSOR2 ECM ENGINE COOLANT TEMPERATURE (ECT) SENSOR3 ECM ECT SENSOR HARNESS CONNECTOR4 PCM ECT SENSOR HARNESS CONNECTOR

Fig. 26 Top Dead Center Alignment Tool Access Hole

1 TORQUE CONVERTER BOLT ACCESS HOLE2 ENGINE OIL PAN3 TOP DEAD CENTER ALIGNMENT TOOL ACCESS HOLE




17/38

D. C . Remove the a l ignment tool f rom the t r ans -mission adapter plate.(15) Remove access plug and plug washer a t rear

of pump (Fig. 27). Thread special dial indicator andada pter tool VM# 1011 (Fig . 28) in to th is opening.Hand tighten only.

(16) Slowly rota te the engine in a counter-c lock-wise d irect ion un t il t he d ia l gauge indica to r s topsmoving (20 -25 before T. D. C.).

(17) Remove the in ject ion pump dr ive gear nut(Fig. 29).

(18) A special 3piece gear removal tool set VM#1003 (Fig. 30) must be used to remove the injectionpump dr ive gear f rom the pump shaf t .

Fig. 27 Access Plug at Rear of Pump 1 ACCESS PLUG2 WASHER

Fig. 28 Installing Dial Indicator and Special Adapter Tools

1 DIAL INDICATOR TOOL2 ADAPTER TOOL VM1011

Fig. 29 Removing Pump Drive Gear Nut 1 TIMING GEAR COVER2 INJECTION PUMP GEAR3 PUMP GEAR NUT

Fig. 30 Pump Gear Tools 1 DRIVE BOLT2 TIMING COVER ADAPTER3 GEAR PULLER




18/38

(a) Thread the ada pter (Fig . 31) in to the t imingcover.

(b ) Thread the gea r pul le r in to the in ject ionpump drive gear (Fig. 31). This tool is also used toh ol d t h e g ea r i n s yn ch r on iz a t ion d ur in g p um premoval.

(c) Remove the three in ject ion pumptogearcover mount ing nuts (Fig . 32). CAUTION: Thisstep must be done to prevent injection pumpdamage.

(d ) Ins t a l l t he d r ive bol t i n to the gea r pul le r(Fig. 31). Tighten the drive bolt to press (remove)the d r ive gea r f rom in ject ion pump sha f t wh i ledr iving in ject ion pump rearwa rd f rom t iming gearcover mounting studs.

(19) Remove pump from engine. Do not rotateengine while gear puller is installed. Engine

damage will occur.

INSTALLATION / ADJUSTING INJECTION PUMPTIMING

NOTE: Engine should be positioned at 20- 25degrees before T. D. C.

(1) Clean the mat ing surfaces of in ject ion pumpand timing gear cover.

(2) Ins ta l l a new inject ion pumptot iming gearcover gasket.

(3) Remove the gea r r emoving bol t (d r ive bol t )from gear puller. CAUTION: Do not remove thespecial gear puller or timing cover adaptertools from timing cover at this time. Gear mis-alignment will result.

(4) Place the key way on the pump shaf t to the 11oclock posi t ion as viewed from the f ront of pump.Ins ta l l t he pump in to the r ea r o f t iming gea r coverwhi le a l igning the key wa y on pump shaf t in to pumpgear.

(5) Ins ta l l and snug the 3 in ject ion pump mount-ing nuts. This is not the final t ightening sequence.

(6) Remove the specia l gea r pul ler and adap tertools from timing gear cover.

(7) In s ta l l t h e i nject i on pu m p d ri ve g ea r n u t.Torque the nut to 86 Nm.

(8) Remove t he access p lug and p lug washer a trear of pump (Fig. 33). Thread special dial indicatorada pter tool VM# 1011 (Fig . 34) in to th is opening.Ha nd t ighten only.

(9) At ta ch specia l d ia l indicat or tool VM# 1013into the adapter tool (Fig. 34)

(10) Us ing a socket a t t a ched to the f ron t of the

cranksha ft , r otate the engine in a counter-clockwisedirection untilthe d ia l gauge indica to r s tops moving (20 -25

before T. D. C.).(11) Set t he dia l indicator t o 0 mm. B e sure the t ip

of the d ia l indica to r i s touch ing the t ip ins ide theadapter tool.

(12) Rota te the crankshaf t clockwise un t il t hea l ignment tool can be r einsta l l ed in the f lexp la te(Fig. 35).

Fig. 31 Installing Pump Drive Gear Removal Tools 1 ADAPTER2 DRIVE BOLT3 GEAR PULLER

Fig. 32 Injection Pump Mounting Nuts 1 MOUNTING FLANGE2 SLOTTED HOLES (3)

3 PUMP MOUNTING NUTS (3)




19/38

NOTE: Engine must be positioned at T. D. C. #1 cyl-inder compression stroke.

(13) The gauge reading should be a t 0 .45 mm. I fnot , the pump must be rota ted for adjustment :

NOTE: If the engine is fitted with all new gears, thespecification is 0.49 - 0.50 mm.

(a) Loosen the three in ject ion pump mount ingnu t s a t t he mount ing f langes . These f langes a reequipped with slotted holes. The slotted holes areused to rotate and position the injection pump forfuel t iming. Loosen the three nuts jus t enough torota te the pump.

(b) Rotate the pump unt i l 0 .45 mm is indicatedon the d ia l ind ica to r gauge . I f wh i l e ro ta t ing thepump the 0 .45 mm specif icat ion is passed do nota t tempt to rota te the pump in the opposi te d i rec-t ion. You must rota te the pump back to 0 .15 mmand s tar t the procedure over f rom the s tar t of theT. D . C . procedure. This will prevent a false rea d-ing due to gear backlash.

(c) Tighten t he th ree pump mounting nuts to 30Nm (22 ft . lbs.) torque.

(d) Recheck the dia l indicator af ter t ighteningthe pump mount ing nu t s . G auge should s t il l bereading 0 .45 mm a t T. D . C.(14) Remove the dial indicator and adapter tools.(15) In s ta l l a c ces s p lu g a n d w a s h er t o r ea r of

injection pump.(16) Install plug at t iming gear cover.

Fig. 33 Access Plug at Rear of Pump 1 ACCESS PLUG2 WASHER

Fig. 34 Installing Dial Indicator and Special Adapter Tools

1 DIAL INDICATOR TOOL2 ADAPTER TOOL VM1011

Fig. 35 Top Dead Center Alignment Tool Access Hole

1 TORQUE CONVERTER BOLT ACCESS HOLE2 ENGINE OIL PAN3 TOP DEAD CENTER ALIGNMENT TOOL ACCESS HOLE




20/38

(17) Inst all and connect the five highpressure fuell ines to the fuel in ject ion pump. Also connect fuell ines a t the fuel in jectors. For procedures , refer toHighPressure Fuel Lines in th is group.

(18) Inst all electrical connector at engine coolan ttemperature sensor.

(19) Connect electrical connector at fuel shutdownsolenoid.(20) Connect the ma in eng ine wi r ing ha rness to

the glow plugs.(21) Connect the fuel t iming solenoid pigta i l har-

ness to the engine wir ing harness .(22) C onnect th e overflow va lve/ban jo fittin g (fuel

return line assembly). Replace copper gaskets beforeinstall ing.

(23) Connect the rubber fue l r etu rn and supp lyhoses t o metal l ines a t pump. Tighten hose clam ps to2 Nm (20 in. lbs.) torque.

(24) Install the generator assembly. Refer to Group

8C, Charging System for the procedure.(25) Ins ta l l the engine accessory dr ive bel t . Refer

to Group 7, Cooling System for the procedure.(26) Posi t ion the gasket and Ins ta l l the in take a i r

duct on the in take manifold . Torque t he bol ts to 27Nm (20 ft. lbs.).

(27) Inst all the int ercooler outlet hose on the int er-cooler.

(28) Connect the negative battery cable.(29) Star t the engine and br ing to normal operat -

ing temperature.(30) Check for fuel leaks.

FUEL INJECTORSFour fuel in jector s a re used on each eng ine. Of

these four, two d iffe rent types a re used . The fue lin jector used on cyl inder number one is equippedwith a fuel injector sensor (Fig. 36). The other threefuel injectors are identical. Do not place the fuelinjector equipped with the fuel injector sensorinto any other location except the cylindernumber one position.

REMOVAL(1) Disconnect negative battery cable at battery.(2) Thoroughly clean the area ar ound th e injector

with compressed air.(3) Remove the fuel d ra in hoses (tubes ) a t each

injector (Fig. 37) being serviced. Each of these hosesis slipfit to the fi t t ing on injector.

(4) Remove the highpressure fuel l ine at injectorbeing removed. Refer to HighPressure Fuel Lines inthis group for procedures.

(5) Remove the injector using special socket toolnumber VM.1012B. When removing cylinder numberone in jector, thread the wir ing harness through theaccess hole on the special socket (Fig. 38).

(6) Remove and discar d t he copper w ash er (seal) atbottom of injector (Fig. 36).

Fig. 36 Fuel Injector Sensor #1 Cylinder 1 NEEDLE MOVEMENT SENSOR2 FUEL INJECTOR (NUMBER 1 CYLINDER ONLY)3 COPPER WASHER4 SENSOR CONNECTOR

Fig. 37 Fuel InjectorTypical 1 FUEL INJECTOR2 LINE FITTING3 HIGH-PRESSURE FUEL LINE4 FUEL DRAIN TUBES




21/38


22/38

SPECIFICATIONS

FUEL TANK CAPACITY78 Liters (20.5 Gals.)Nomina l r ef il l capac it i es a re shown. A va r ia t ion

may be observed from vehicle to vehicle due to man-

ufactu r ing tolerances, ambien t t empera tu res andrefill procedures.

IDLE SPEED750 RPM 25 RPM wi th engine a t normal oper-

a t ing t emperature .

FUEL INJECTOR FIRING SEQUENCE12453

FUEL SYSTEM PRESSUREPeak Injection Pressure/Fuel Injection Pump

Operating Pressure: 40,00045,000 kP a (5801

6526 psi).Opening Pressure of Fuel Injector:

16,50017,300 kP a (23932509 psi).



23/38

FUEL INJECTION SYSTEM3.1L DIESEL ENGINE

TABLE OF CONTENTS

page page

DESCRIPTION AND OPERATIONAIR CONDITIONING (A/C) CONTROLSECM

INPUTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27AIR CONDITIONING RELAYECM OUTPUT . . . . 28ASD RELAYECM INPUT . . . . . . . . . . . . . . . . . . 27BATTERY VOLTAGEPCM INPUT. . . . . . . . . . . . 25BOOST / PRESSURE SENSOR . . . . . . . . . . . . . . 24BRAKE SWITCHECM INPUT. . . . . . . . . . . . . . . 27DATA LINK CONNECTORPCM AND ECM

INPUT AND OUTPUT . . . . . . . . . . . . . . . . . . . . 27ELECTRIC VACUUM MODULATOR (EVM)

ECM OUTPUT. . . . . . . . . . . . . . . . . . . . . . . . . . 30ENGINE COOLANT GAUGEPCM OUTPUT . . . . 28ENGINE COOLANT TEMPERATURE

SENSORECM/PCM INPUT. . . . . . . . . . . . . . . 26ENGINE OIL PRESSURE GAUGEPCM

OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28ENGINE SPEED/CRANK POSITION

SENSORECM INPUT. . . . . . . . . . . . . . . . . . . 26FIVE VOLT POWERECM/PCM OUTPUT . . . . . . 28FUEL INJECTION SYSTEM . . . . . . . . . . . . . . . . . 23FUEL INJECTOR SENSORGROUND. . . . . . . . . 26GLOW PLUG LAMPPCM OUTPUT . . . . . . . . . . 28GLOW PLUG RELAYECM OUTPUT . . . . . . . . . 28

GLOW PLUGS . . . . . . . . . . . . . . . . . . . . . . . . . . . 29IGNITION CIRCUIT SENSEPCM/ECM INPUT . . 25NEEDLE MOVEMENT OR INTRUMENTED

FIRST INJECTORECM INPUT . . . . . . . . . . . . 25POWER GROUND . . . . . . . . . . . . . . . . . . . . . . . . 25POWERTRAIN CONTROL MODULE (PCM)

AND ENGINE CONTROL MODULE (ECM). . . . . 24

SENSOR RETURNECM/PCM INPUT(ANALOG GROUND). . . . . . . . . . . . . . . . . . . . . 25

SPEED CONTROLECM INPUT . . . . . . . . . . . . . 27SPEED CONTROLPCM OUTPUTS . . . . . . . . . . 28TACHOMETERPCM OUTPUT . . . . . . . . . . . . . . 28TIMING SOLENOIDECM OUTPUT . . . . . . . . . . 28VEHICLE THEFT ALARM . . . . . . . . . . . . . . . . . . . 25

DIAGNOSIS AND TESTINGASD RELAY TEST . . . . . . . . . . . . . . . . . . . . . . . . 30BOOST / PRESSURE SENSOR . . . . . . . . . . . . . . 33DIAGNOSTIC TROUBLE CODES . . . . . . . . . . . . . 33DIESEL DIAGNOSTICS . . . . . . . . . . . . . . . . . . . . 30ENGINE COOLANT TEMPERATURE SENSOR

TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30ENGINE SPEED SENSOR TEST . . . . . . . . . . . . . 30GLOW PLUG RELAY TEST . . . . . . . . . . . . . . . . . 31GLOW PLUG TEST . . . . . . . . . . . . . . . . . . . . . . . 31RELAYSOPERATION/TESTING. . . . . . . . . . . . . 32VEHICLE SPEED SENSOR TEST. . . . . . . . . . . . . 33

REMOVAL AND INSTALLATIONA/C CLUTCH RELAY . . . . . . . . . . . . . . . . . . . . . . 34ASD RELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34ENGINE COOLANT TEMPERATURE SENSOR. . . 36ENGINE SPEED SENSOR . . . . . . . . . . . . . . . . . . 34

GLOW PLUGS . . . . . . . . . . . . . . . . . . . . . . . . . . . 37SPECIFICATIONSGLOW PLUG CURRENT DRAW. . . . . . . . . . . . . . 38TORQUE CHART3.1L DIESEL. . . . . . . . . . . . . . 38

DESCRIPTION AND OPERATION

FUEL INJECTION SYSTEM

DESCRIPTIONThis section will cover components either regulated

or control led by the ECM control ler and the Power-t ra in Control Module (P CM). The fuel heater re layand fuel heater are not operated by the ECM control-ler or the PCM. These components are controlled bythe ignition (key) switch. All other fuel system elec-t r ical components necessary to operate the engineare controlled or regulated by the ECM controller,which in terfaces wi th the PCM. Refer to the fol low-ing description for more information.

Cer ta in fuel sys tem component fa i lures ma y causea no s tar t , or prevent the engine f rom running. I t i sim por ta n t t o kn ow t ha t t he E C M h a s a fea t ur ewhere, if possible, i t will ignore the failed sensor, seta code re la ted to the sensor, and operate the enginein a Limp Home mode. When the ECM is operatingin a Limp Home mode, t he Check E ngine Lamp onthe ins t rument panel may be constant ly i l luminated,and the engine will most l ikely have a noticeable lossof per formance . An example of th i s would be anAccelerator Pedal Position Sensor failure, and in thats itua t ion , the eng ine w ould run a t a cons tan t 1100RPM, regardless of the actual posi t ion of the pedal .This is the most extreme of the three Limp Homemodes.



24/38

When t he C heck Engine La mp is i lluminated con-s t an t ly wi th the key on and the eng ine runn ing , , i tusually indicates a problem has been detected some-where wi thin the fuel sys tem. The DRB III scan toolis the best method for communicat ing wi th the ECMand PCM to d iagnose f au l t s wi th in the system.

POWERTRAIN CONTROL MODULE (PCM) ANDENGINE CONTROL MODULE (ECM)

The Eng ine Con t rol Module (ECM) i s moun tedunderneath the lef t rear seat . The Powert ra in Con-t rol Module (P CM) i s moun ted in the eng ine com-par tment .

The E CM C ontroller is a preprogram med, digitalcomputer. I t wi l l e ither d i rect ly operate or par t ia l lyregulate the:

Speed Control Speed Control lamp Fuel Timing Solenoid Check Engine Light G low P lug Re lay G low P lugs G low P lug Lamp ASD Relay Air Conditioning Tachometer Electric Vacuum Modulator (EVM)Th e E C M ca n a d a pt i ts pr og ra m m in g t o m eet

changing operating conditions.Th e E C M r ecei ves i npu t s ig n a ls f rom v a r iou s

s w it ch es a n d s en s or s. B a s e d on t h es e i npu t s, t h eECM regulates various engine and vehicle operationsthrough different system components. These compo-nents are referred to as ECM Outputs. The sensorsa n d s w it ch es t h a t pr ov id e i n pu t s t o t h e E C M a r econsidered ECM Inputs.

ECM Inputs are: Air Conditioning Selection Theft Alarm ASD Relay Control Sleeve Position Sensor Fuel Temperat ure S ensor Mass Air Flow Sensor Accelerator Pedal Position Sensor

E ngine C oolant Tempera ture Sensor Low Idle Posi t ion Switch 5 Volt Supply Vehicle Speed Sensor Eng ine Speed/Cra nk P osition S ensor (rpm) Needle Movement Sensor S t a r t e r S igna l B rake Swi tch Speed Control Switch Power Ground Ignition (key) Switch SenseECM Outputs:

Afte r inpu t s a re r ece ived by the ECM and PCM,cer ta in sensors , swi tches and components are con-t rolled or regulated by the E CM a nd P CM. These areconsidered ECM Outputs. These outputs ar e for:

A/C Clu tch Rela y (for A/C clutch operat ion) S peed Control La mp

ASD Relay 5 Volts Supply Fuel Quantity Actuator Fuel Timing Solenoid Fuel Shutdown Solenoid G low P lug Lamp C heck Engine La mp (On/Off signa l) Electric Vacuum Modulat or (EVM) G low P lug Re lay TachometerThe PCM sends and receives s ignals to and f rom

the ECM controller. PCM inputs are: Power Ground 5 Volts Supply Vehicle Speed Sensor Water-In-Fuel Sensor Coolan t Temperat ure S ensor Low Coolant Sensor Sensor Return Fuel Level Sensor Oil Pressure Sensor Ta chometer S igna l G low P lug Lamp C heck Engine La mp (On/Off signa l) B rake On/Off S witch B at t ery Vol tage ASD RelayPCM Outputs: A/C On Sign a l Vehicle Theft Alarm Ok to Run signal B ody Control Module CCD Bus (+ ) Body Control Module CCD Bus () S can Tool D at a Link Receive S can Tool D at a Link Tra nsmit Low Coolant Lamp Generator Control

BOOST / PRESSURE SENSORThe B oost P ressure Sensor is mounted to t he top of

the in take manifold (Fig . 1) . I t i s a sensor that mea-sures both manifold vacuum and turbo boost , and i ta l so con ta ins an in teg ra ted in take a i r t empera tu resensor. The Boost Pressure Sensor takes the place ofthe Mass Air F low (MAF). In the Inta ke Air Temper-at ure S ensor component , there is a ceramic e lementtha t changes i t s r es is t ance based on t empera tu re.The ceramic element is part of a n electronic circuitconnected to the P CM, a nd has a vol t age appl ied toi t . The ceramic e lement is exposed to the a i r ins idet h e i nt a k e. Th is a i r h a s a cool in g ef fect on t h e




25/38

ce ramic e lement , and i t s r es is t ance changes . Th i scauses the vol t age f lowing th rough the in take a i rtemperature ci rcui t to vary. The vol tage s ignal pro-duced by t he I nta ke Air Temperat ure S ensor changesinversely to t he temperature , a nd is measured by t heP CM. As a general ru le, w hen the t emperature of the

air in the in take is h igh, t he volta ge s ignal producedby the Inta ke Air Temperature Sensor is low. Thecomponen t of the Boos t P ressure Sensor tha t mea-sures manifold vacuum a nd turbo boost produces avol tage s ignal that i s propor t ional to t he pressure inthe intake manifold. When the intake manifold pres-sure is low, the voltage is low, and when the pressureis h igh, the vol tage is h igh. The PCM uses the vol t -age s ignals f rom the Boost Pressure Sensor, and theIn take Ai r Tempera tu re Sensor to dete rmine theamount of a i r f lowing through the in take manifold .

VEHICLE THEFT ALARM

DESCRIPTIONThe PCM can l ea rn i f t he veh icle has a Vehicle

Theft Alarm (VTA) syst em. Once it detects the vehi-

cle ha ving VTA, the controller can ONLY BEUSED ON VEHICLES WITH VTA.I f t he P CM is put i t on a vehicle wi thout VTA the

Glow P lug Lamp wi l l s t a r t t o b l ink and the veh ic lewi l l not s t a r t .

The P CM cannot be flashed to remove the VTA.

BATTERY VOLTAGE PCM INPUT

DESCRIPTIONThe bat tery vol tage input provides power to the

P CM. I t a l so in forms the PCM wha t vol t age l evel i sbeing supplied by the generator once the vehicle is

running.The bat tery input a lso provides the vol tage tha t i s

needed to keep the PCM memory alive. The memorystores Diagnost ic Trouble Code (DTC) messages .Trouble codes w ill st i l l be st ored even if th e ba tta ryvoltage is lost .

SENSOR RETURN ECM/PCM INPUT (ANALOGROUND)

DESCRIPTIONSensor Return provides a low noise Analog ground

reference for all system sensors.

IGNITION CIRCUIT SENSE PCM/ECM INPUThe ignit ion c ircui t sense input s ignals t he P CM

a n d E C M t h a t t h e i gn it i on (k ey ) s w i t ch h a s b eenturned to the ON posi t ion. This s ignal in i t ia tes theg low p lug con t rol rou t ine to beg in the prehea tcycle.

POWER GROUND

DESCRIPTIONProvides a common ground for power devices (sole-

noid and relay devices).

NEEDLE MOVEMENT OR INTRUMENTED FIRINJECTOR ECM INPUT

This input f rom the E CM supplies a constant 30mA electrical current source for the first injector sen-sor. I t w i ll va ry the vo lt age to th i s sensor when i tsenses a mechanical movement wi thin the in jectorneedle (pintle) of the number1 cylinder fuel injector.When this vol tage ha s been determined by the E CM,i t wi l l then control an output t o the fuel t iming sole-noid (the fuel t iming solenoid is located on the fuelinjection pum p). Also refer t o Fuel I njection P ump foradditional information.

The first injector sensor is a ma gnetic (inductive)type.

The f irs t in jector sensor is used only on the fuelinjector for the number1 cylinder (Fig. 2).

Fig. 1 Boost Pressure Sensor Location 1 BOOST PRESSURE SENSOR HARNESS CONNECTOR2 BOOST PRESSURE SENSOR




26/38

FUEL INJECTOR SENSOR GROUND

DESCRIPTIONP rovides a low noise ground for the fuel in jector

sensor only.

ENGINE COOLANT TEMPERATURE SENSORECM/PCM INPUT

DESCRIPTIONThe 05 volt input from this sensor tells the ECM

a n d P C M t h e t em per a t u re of t h e en gi ne cool a n t .B a s e d on t h e v ol t a ge r ecei ved a t t h e E C M , i t w i llthen determine operation of the fuel t iming solenoid,glow plug relay, electrical vacuum modulat or (emis-sion component) and generator (charging system).

The sensor is located on th e side of t he #3 cylinderhead near the rear of fuel injection pump (Fig. 3).

ENGINE SPEED/CRANK POSITION SENSORECM INPUTThe engine speed sensor is mounted to the t rans-

miss ion bel lhous ing a t the r igh t /r ea r s ide of theengine block (Fig. 4).

The engine speed sensor produces i ts own outputsignal. If this signal is not received, the ECM will nota l low the engine to s tar t .

The engine speed sensor input is used in conjunc-t ion wi th the f irs t in jector sensor to es tabl ish fuelinjection pump timing.


Fig. 3 Engine Coolant Temperature Sensor Location 1 PCM ENGINE COOLANT TEMPERATURE (ECT) SENSOR2 ECM ENGINE COOLANT TEMPERATURE (ECT) SENSOR3 ECM ECT SENSOR HARNESS CONNECTOR4 PCM ECT SENSOR HARNESS CONNECTOR

Fig. 4 Engine Speed Sensor Location 1 ENGINE SPEED SENSOR RETAINING BOLTS2 RUBBER GASKET3 ENGINE SPEED SENSOR




27/38

The f lywhee l has f ive notches a t i t s ou ter edge.Each notch is spaced equally every 72. The notchescause a pulse to be generated when they pass underthe speed sensor. These pulses are the input to theECM. The input f rom this sensor determines crank-sha ft position (in degrees) by monitoring th e notches.

The sensor a l so genera tes an rpm s igna l to t heECM. This s ignal i s used as an input for the controlof the genera to r f ie ld , veh icle speed con t rol , andinstrument panel mounted tachometer.

I f the engine speed sensor should fa i l , the systemis unable to compensate for the problem and the carwill stop.

AIR CONDITIONING (A/C) CONTROLS ECMINPUTS

DESCRIPTIONThe A/C contr ol syst em informa tion a pplies to fa c-

tory installed air conditioning units.A/C REQUEST SIGNAL: When eith er th e A/C or

Defrost mode has been selected an d the A/C low an dhighpressure switches are closed, an input signal issent to the ECM. The ECM uses th is input to cycleth e A/C compressor th rough th e A/C rela y.

If the A/C low or highpressure swit ch opens, theECM wi ll not r ece ive an A/C reques t s igna l . TheP CM will t hen remove th e ground from t he A/C r elay.This w ill dea ctiva te th e A/C compressor clutch. Also,i f t he engine coolant reaches a temperature outs idenormal of i t s normal range, or i t overheats , the ECMwill deact ivat e th e A/C clutch.

BRAKE SWITCH ECM INPUT

DESCRIPTIONWhen the brake l ight sw i tch is ac t ivated, the E CM

r ecei ves a n i npu t i nd ica t i n g t h a t t h e b ra k es a r ebeing applied. After receiving this input, the ECM isused to control the speed control system. There is aPr imary and a Secondary brake switch. The Second-a ry b rake swi tch i s c losed un t i l t he b rake peda l i spressed.

DATA LINK CONNECTOR PCM AND ECMINPUT AND OUTPUTThe 16way data l ink connector (diagnost ic scan

tool connector ) l inks the Diagnos t i c Readou t Box(DRB) scan too l wi th the PCM and ECM. The da talink connector is located under the instrument panelnear the lef t body s ide cowl panel on lef t hand dr ivevehicles (Fig . 5). And near the r ight body s ide cowlpanel on right hand drive vehicles.

SPEED CONTROL ECM INPUT

DESCRIPTIONThe speed control system provides f ive separa te

inputs to th e E CM: On/Off, S et, Resume/Accel, C a ncel,

and Decel.. The On/Off input informs the E CM tha t thespeed control system has been activated. The Set inputinforms t he E CM tha t a f ixed vehicle speed ha s beenselected. The Resume input indicates to the ECM thatthe previous fixed speed is requested.

Speed control opera tion w ill sta rt at 50 km/h142km/h (3585 mph). The upper r a nge of operat ion isnot rest r icted by vehicle speed. Inputs that effectspeed control operation are vehicle speed sensor andaccelerator pedal position sensor.

Refer to Group 8H for further speed control infor-mat ion.

ASD RELAY ECM INPUTDESCRIPTION

A 12 vol t s ignal a t th is input indica tes to the ECMtha t the ASD relay has been a ctivated. The ASD relay islocated in the PDC. The PDC is located next to the bat-tery in the engine compartment. For the location of therelay within the PDC, refer to label on PDC cover.

This input is used only to sense that the ASD relayis energized. If the ECM does not see 12 volts (+ ) atthis input when the ASD relay should be activated, i tw ill set a Dia gnostic Trouble Code (DTC).

Fig. 5 Data Link Connector Location L. H. D.1 INSTRUMENT PANEL LOWER/LEFT EDGE2 DATA LINK CONNECTOR




28/38

FIVE VOLT POWER ECM/PCM OUTPUT

DESCRIPTIONThis ci r cu it supp li es approx imate ly 5 vol t s to

power the Accelerator Pedal Position Sensor, and theBoost Pressure Sensor.

ENGINE COOLANT GAUGE PCM OUTPUT

DESCRIPTIONRefe r to the Ins t rument Pane l and Gauges g roup

for additional information.

ENGINE OIL PRESSURE GAUGE PCMOUTPUT

DESCRIPTIONRefe r to the Ins t rument Pane l and Gauges g roup

for additional information.

GLOW PLUG LAMP PCM OUTPUT

DESCRIPTIONThe Glow P lug la mp (malfunct ion indicat or lamp)

illuminates on the message center each time the igni-t ion (key) swi tch i s tu rned on . I t w i ll s t ay on forabout two seconds as a bulb tes t .

SPEED CONTROL PCM OUTPUTSDESCRIPTION

These two circui ts control the fuel quant i ty actua-tor to regulate vehicle speed. Refer to Group 8H forSpeed Control information.

AIR CONDITIONING RELAY ECM OUTPUT

DESCRIPTIONThis circuit controls a ground signa l for operation

of t he A/C clutch relay. Also refer to Air C onditioning(A/C) ControlsEC M Input for addit iona l informa -tion.

The A/C relay is located in the P ower D istributionCenter (PDC). The PDC is located next to the batteryin the engine compartment . F or the locat ion of t herelay wi thin the PDC, refer to label on PDC cover.

TIMING SOLENOID ECM OUTPUT

DESCRIPTIONThe t iming solenoid is locat ed on the bott om of the

fuel injection pump (Fig. 7).

This 12(+ ) volt, pulse width modulated (dutycycle)output controls the amount of fuel t iming (advance)in the fuel injection pump. The higher the dutycy-cle, the lower the advance. The lower the dutycycle,the more advanced the fuel t iming.

The du tycycle i s dete rmined by the ECM f rominputs i t receives f rom the fuel in jector sensor andengine speed sensor.

TACHOMETER PCM OUTPUT

DESCRIPTIONThe PCM recieves eng ine rpm va lues f rom the

ECM controller, and then supplies engine rpm valuesto the Body Control ler that then suppl ies the ins t ru-ment cluster mounted tachometer (if equipped). Referto Group 8E for tachometer information.

GLOW PLUG RELAY ECM OUTPUTWhen the ignition (key) switch is placed in the ON

posi t ion, a s ignal i s sent to the ECM rela t ing currentengine coolant temperature. This signal is sent fromthe engine coolant temperature sensor.

After receiving this signal, the ECM will determinei f, when a nd for how long a per iod the g low p lugrelay should be a ctivated. This is done before, duringand af ter the engine is s tar ted. Whenever the glow plug re lay is a c t ivated, i t wi l l control the 12V+ 100amp circuit for the operation of the four glow plugs.

Fig. 6 Glow Plug Lamp Symbol

Fig. 7 Timing Solenoid 1 FUEL INJECTION PUMP ASSEMBLY2 FUEL RETURN LINE3 FUEL SUPPLY LINE4 FUEL INJECTION PUMP 10WAY CONNECTOR5 TIMING SOLENOID6 OVERFLOW VALVE




29/38

With a cold engine, the glow plug re lay and glow p lugs may be ac t iva ted for a max imum t ime of 200seconds. Refer to the fol lowing G low P lug Controlchar t for a tempera tur e/time comparison of glow plugrelay operation.

I n t h i s c h a r t , P r e H e a t a n d P o s t H e a t t i m e s a r ement ioned. Preheat i s the amount of t ime the glow

plug relay circuit is activated when the ignition (key)swi tch i s ON, bu t the eng ine has ye t to be s t a r t ed .Postheat i s the amount of t ime the glow plug re laycircuit is activated after the engine is operating. TheGlow P lug l amp wi l l no t be i llumina ted dur ing thepostheat cycle.

GLOW PLUGS

DESCRIPTIONGlow p lugs a re used to help s t a r t a cold o r cool

eng ine . The p lug wi l l hea t up and g low to hea t thecombustion cha mber of each cylinder. An individualplug is used for each cylinder. Each plug is threadedinto t he cyl inder head above the fuel in jector (Fig .10).

Each plug will momentarily draw approximately 25amps of e lect r ical current dur ing t he in i t ia l keyoncycle. This is on a cold or cool engine. After hea ting,the cu r ren t d raw wi l l d rop to approx imate ly 912amps per plug.

Total m omenta ry current dra w for a ll four plugs isapproximat ely 100 a mps on a cold engine dropping t oa to ta l of approximately 40 amps af ter the plugs areheated.

Electrical operat ion of the glow plugs ar e controlledby the glow plug relay. Refer to the previous Glow PlugRelayECM Output for additional information.

CAV COLOR FUNCTION

30 RD/DB FUSED B(+)

85 DB/WT FUSED ASDRELAY OUTPUT

86 WT GLOW PLUGRELAY #1CONTROL

87 GY GLOW PLUGRELAY #1OUTPUT


CAV COLOR FUNCTION

30 VT/RD FUSED B(+)

85 DB/WT FUSED ASDRELAY OUTPUT

86 LB/WT GLOW PLUGRELAY #2CONTROL

87 GY/YL GLOW PLUGRELAY #2OUTPUT


GLOW PLUG CONTROL

ENGINECOOLANTTEMPER-

ATURE KEYON

WAIT-TO-START

LAMP ON(SECONDS)

PRE-HEATCYCLE(GLOW

PLUGS ON)(SECONDS)

POST-HEATCYCLE

(SECONDS)

-30 C 15 SEC. 45 SEC. 200 SEC.

-10 C 8 SEC. 35 SEC. 180 SEC.

+10 C 6 SEC. 25 SEC. 118 SEC.

+30 C 5 SEC. 20 SEC. 70 SEC.

+40 C 4 SEC. 16 SEC. 60 SEC.

+70 C 3 SEC. 16 SEC. 20 SECC.

Fig. 10 Glow Plug 1 GLOW PLUG




30/38

ELECTRIC VACUUM MODULATOR (EVM) ECMOUTPUT

DESCRIPTIONThis circuit controls operation of t he Electric Vac-

uum Modulator (EVM). The EVM controls operationof the EG R va lve .

Refer t o G roup 25, Emiss ion Control System forinforma tion. S ee E lectric Vacuum Modulat or.

DIAGNOSIS AND TESTING

DIESEL DIAGNOSTICSThe EC M controllers perform engine off dia gnostic

tes ts , which ma y be heard for about 60 seconds a f terturning t he key off .

ASD RELAY TESTTo perform a tes t of the re lay and i ts re la t ed c i r-

cui t ry, refer t o the DRB scan tool . To tes t the re layonly, refer to Relay sOpera tion/Testing in this sec-tion of the group.

Diagnostic Trouble Codes: Refer to On-BoardDiagnost ics in Group 25, Emiss ion Control Systemfor a list of Dia gnostic Trouble Codes (DTCs) for cer-tain fuel system components.

ENGINE SPEED SENSOR TESTTo perform a tes t of the engine speed sensor and

i t s r el a t ed ci r cu it ry, r efer to the 3.1L Powert ra in

Diagnostic Procedures Manual.Diagnostic Trouble Codes: Refer to On-BoardDiagnost ics in Group 25, Emiss ion Control Systemfor a list of Dia gnostic Trouble Codes (DTCs) for cer-tain fuel system components.

ENGINE COOLANT TEMPERATURE SENSORTEST

The sensor is located on the side of cylinder headnear the rear of fuel injection pump (Fig. 11).

For a l ist of D iagnostic Trouble C odes (DTCs) forcer ta in fuel sys tem components , refer to On-BoardDiagnost ics in Group 25, Emiss ion Control System.To t est the sensor only, refer to the following:

(1) Disconnect wire harness connector from coolanttemperature sensor.

(2) Test t he res is tance of the sensor wi th a highinput impedan ce (digita l) voltohmmeter. The resis-t a n ce (a s m ea s u red a c ros s t h e s en s or t er m in a l s)s h ou ld b e l es s t h a n 1340 oh m s w i t h t h e en gi new a r m . R ef er t o t h e f ol low i n g S en s or R es is t a n ce(OHMS) char t . Replace the sensor i f i t i s not wi thinthe range of res is tance specif ied in the char t .

Fig. 11 Engine Coolant Temperature Sensor Location

1 PCM ENGINE COOLANT TEMPERATURE (ECT) SENSOR2 ECM ENGINE COOLANT TEMPERATURE (ECT) SENSOR3 ECM ECT SENSOR HARNESS CONNECTOR4 PCM ECT SENSOR HARNESS CONNECTOR

SENSOR RESISTANCE (OHMS)

TEMPERATURE RESISTANCE (OHMS)

C F MIN MAX

40 40 291,490 381,71020 4 85,850 108,39010 14 49,250 61,430

0 32 29,330 35,99010 50 17,990 21,81020 68 11,370 13,61025 77 9,120 10,88030 86 7,370 8,75040 104 4,900 5,75050 122 3,330 3,880

60 140 2,310 2,67070 158 1,630 1,87080 176 1,170 1,34090 194 860 970

100 212 640 270110 230 480 540120 248 370 410




31/38

(3) Tes t con t inui ty of the wi re ha rness . Do th i sbetween the ECM wi re ha rness connector and thesensor connector terminal . Also tes t cont inui ty ofwire harness to the sensor connector terminal. Referto G roup 8W for wiring connector a nd circuitry infor-mat ion. Repair the wire harness i f an open c i rcui t i s

indicated.(4) After tes ts are completed, connect e lect r icalconnector to sensor.

GLOW PLUG TESTHard s tar t ing or a rough idle af ter s tar t ing may be

caused by one or more defect ive glow plugs . Beforetes t ing the glow plugs , a tes t of the glow plug re laysshould be performed. This wi l l ensure t hat 12V+ isa v a i la b le a t t h e pl ug s w h en s t a r t in g t h e en gi ne.Refer t o the G low P lug Relay Test for informa tion.

For accurate test results, the glow plugs should beremoved from the engine. The plugs must be checked

when cold. Do not check the plugs i f the enginehas recently been operated. If plugs arechecked when warm, incorrect amp gaugereadings will result.

U s e C h ur ch il l G l ow P l u g Tes t er D X. 900 or a nequiva len t (F ig. 12) for the fol lowing t e st s . Th i stes ter i s equipped with 4 t imer lamps.

(1) Remove the glow plugs from the engine. R eferto G low P lug Removal/Insta llation.

(2) At tach the red lead of the tes ter to the 12V+(positive) side of the bat tery.

(3) At ta ch the black lead of t he tes ter t o the 12V(negative) side of the battery.

(4) Fi t the glow plug into the top of the tes ter andsecure i t with the spring loaded bar (Fig. 12).(5) At tach the th i rd lead wire of the tes ter to the

elect r ical terminal a t the end of t he glow plug.(6) When performing the tes t , the tes ter but ton

(Fig. 12) should be held continuously w ithout releasefor 20 seconds a s indica ted by the 4 t imer l amps .Each i llumina ted l amp represent s a 5 second t imelapse.

(a ) P ress and hold the t e st e r bu t ton (F ig. 12)and note the amp gauge reading. The gauge read-ing should indicate a momentary, in it ia l currentdraw (surge) of a pproximat ely 25 amps. After the

ini t ia l surge, the amp gauge reading should beginto fa l l off . The glow plug t ip should s tar t to glow an orange color af ter 5 seconds. I f the t ip did notglow after 5 seconds, replace the glow plug. Beforediscarding the glow plug, check the position of thecircuit breaker on the bottom of the plug tester. I tmay have to be reset . Reset i f necessary.

(b ) C on t in u e t o h ol d t h e t es t er b ut t on w h il eobse rv ing the amp gauge and the 4 t imer l amps .When al l 4 lamps are i l luminated, indicat ing a 20second t ime lapse , the amp gauge reading shouldindicate a 912 amp current draw. I f not , replacethe glow plug. Refer to G low P lug Removal/Insta l-lation.(7) Check each glow plug in this manner using one

20 second cycle. If the glow plug is to be retested, i tmust first be allowed to cool to room temperature.

WARNING: THE GLOW PLUG WILL BECOMEEXTREMELY HOT (GLOWING) DURING THESETESTS. BURNS COULD RESULT IF IMPROPERLYHANDLED. ALLOW THE GLOW PLUG TO COOLBEFORE REMOVING FROM TESTER.

(8) Remove the glow plug from the tester.

GLOW PLUG RELAY TESTThe glow plug relay is located in the Power Distri-

bution Center (PDC) (Fig. 13) (Fig. 14).When the ignition (key) switch is placed in the ON

posi t ion, a s ignal i s sent to the ECM rela t ing currentengine coolant temperature. This signal is sent fromthe engine coolant temperature sensor.

Fig. 12 Typical Glow Plug Tester 1 INSERT GLOW PLUG HERE2 OBSERVATION WINDOW3 SPRING LOADED BAR4 TIMER LAMPS (4)5 TEST LEADS6 TESTER BUTTON




32/38

After receiving this signal, the ECM will determinei f, when a nd for how long a per iod the g low p lugrelay should be a ctivated. This is done before, duringand af ter the engine is s tar ted. Whenever the glow plug re lay is a ct ivated, i t wi l l control the 12V+ 100amp circuit for the operation of the four glow plugs.

The G low P lug l amp i s t i ed to th i s ci r cu it . Lamp

operation is also controlled by the ECM.With a cold engine, the glow plug re lay and glow p lugs may be ac t iva ted for a max imum t ime of 200seconds. Refer to the Glow Plug Control char t for atempera tur e/time compa rison of glow plug relay oper-ation.

I n t h i s c h a r t , P r e H e a t a n d P o s t H e a t t i m e s a r ement ioned. Preheat i s the amount of t ime the glow plug relay circuit is activated when the ignition (key)swi tch i s ON, bu t the eng ine has ye t to be s t a r t ed .Postheat i s the amount of t ime the glow plug re laycircuit is activated after the engine is operating. The

Glow P lug l amp w i ll not be i llumina ted during thepostheat cycle.

TESTING:Disconnect and isola te the e lect r ical connectors

(Fig. 15) at all four glow plugs. With the engine coolor cold , a nd the key in the

jeep grand cherokee wj_14a-3.1 td- sistema inyección

Documents