197

CONTENTSEMISSION CONTROL SYSTEM (ONLY FOR ELECTRONIC CONTROLLED TYPE) ................ EF-2UNIT LAYOUT .................................................... EF-3SERVICE DATA AND SPECIFICATIONS (SDS) EF-8

Electronic Control System Specifications ....... EF-8LPG FUEL SYSTEM TROUBLE DIAGNOSIS ... EF-9DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM ............................................................ EF-10

Removal and Installation of LPG Injector Drive Unit Connector ..................................................... EF-10Removal and Installation of Electronic Control Throttle Assembly ......................................... EF-10

Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline and Combined Use) ...............................................................EF-11Injector Holder ...............................................EF-15

VAPORIZER MECHANISM AND OPERATION EF-16Primary (Decompression) Room ...................EF-16Description ....................................................EF-19

ENGINE FUEL

SECTION EF

EF

198

EMISSION CONTROL SYSTEM (ONLY FOR ELECTRONIC CONTROLLED TYPE)

Engine type K21, K25

Standard type of fuel deviceGasoline Electronic controlled fuel injection device (Multi-point injection)

LPG Electronic controlled fuel injection device (Single point injection)Air-fuel ratio control type Air-fuel ratio feedback controlStarting auxiliary device Electronic controlled fuel injection

Ignition device Ignition coil electronic controlled distributor integrated with power transistor for each cylinder

Catalytic device Three-way catalyst (Monolith)Braking device With fuel cut device

PCV gas recirculation device Closed type

EF-2

EMISSION CONTROL SYSTEM (ONLY FOR ELECTRONIC CONTROLLED TYPE)

199

UNIT LAYOUT

EFM0089

EF-3

UNIT LAYOUT

200

K-ENGINE ELECTRONIC CONTROLLED SYSTEM DIAGRAM (GASOLINE)

EFM0090

EF-4

UNIT LAYOUT

201

K-ENGINE SYSTEM DIAGRAM (LPG)

EFM0091

EF-5

UNIT LAYOUT

202

FUEL PIPING DIAGRAM

EFM0093

EF-6

UNIT LAYOUT

203

K-ENGINE SYSTEM DIAGRAM (COMBINED USE)

EFM0094

EF-7

UNIT LAYOUT

204 EF-8

SERVICE DATA AND SPECIFICATIONS (SDS)SERVICE DATA AND SPECI-

FICATIONS (SDS)Electronic Control System SpecificationsGasoline electronic injection (injection from each cylinder port)LPG electronic injection (injection from single point on this side ofelectric throttle control actuator)Vaporizer (integrated with electrical PTC heater, water heater) ......Fuel discharge pressure: Approx. 0.3 kgf/cm2Throttle body and injector holder bolts tightening torque (Air hornalso secures.)M8 bolt (thread length : 85, 90, 100 mm): 15.7 - 17.6 Nm (1.6 - 1.8kg-m)

205

LPG FUEL SYSTEM TROUBLE DIAGNOSISCondition Cause Action

Fuel leakage Looseness of piping connection TightenOperating malfunction of vaporizer Repair and adjustPoor connection or some inclusion is caught in between plunger rubber seat and valve seat of solenoid valve

Clean and rub

Operating malfunction of lock off mechanism AdjustmentExcessive fuel consumption Looseness of piping connection Retighten and adjust

Primary side room pressure at idle is excessively high. Clean and adjustClogged air cleaner WashingAdjusting malfunction of LPG mixer main adjusting screw Adjustment

Low output Operating malfunction of vaporizer Repair and adjustLooseness of piping connection or clogged filter Clean and retightenAdjusting malfunction of vaporizer primary and secondary room pressures

Adjustment

Adjusting malfunction of LPG mixer main adjusting screw AdjustmentUse improper fuel. Use proper fuel.Clogged fuel passage Clean

Inconsistent or rough idle Improper position of vaporizer idle adjustment screw or carburetor throttle valve, or operating malfunction of electric throttle control actuator

Adjustment

Operating malfunction of vaporizer Repair and adjustOperating malfunction of vaporizer valve (It is closed improperly.) Clean, adjustment, or replacement

Engine hesitation or hunting Operating malfunction of vaporizer AdjustmentAdjusting malfunction of idle speed Adjustment

Poor starting engine Insufficient fuel Refill fuelOperating malfunction Make sure that manual valve is opened.Operating malfunction of solenoid valve Check and repair wiring, switch, and

solenoid valveOperating malfunction of vaporizer ReplacementWater pump malfunction Repair and adjustAdjusting malfunction of idle speed Adjustment

Operating malfunction of vaporizer

Adjusting malfunction of vaporizer primary and secondary room pressures

Adjustment

Leakage from primary and secondary valve seats of vaporizer Clean, adjust, or replaceDamage of diaphragm ReplacementForeign materials enter vaporizer inside Clean and adjustLeakage by looseness of setscrew TightenOvercool of vaporizer (Fur deposit, damage of hose, poor coolant circulation)

Check, clean, and adjust

Tar deposit in valve Remove tar and clean

EF-9

LPG FUEL SYSTEM TROUBLE DIAGNOSIS

206

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

Removal and Installation of LPG Injector Drive Unit ConnectorREMOVAL1. Pull center of lever forward, and then disconnect tab from lever

and lift it up.2. Raise the lever until it clicks, and fully press the lever to drive

unit side.3. Pull connector forward, and then disconnect it from unit.

INSTALLATION1. Press the lever in drive unit connector while pressing it to

connector end.2. Press in the lever until it clicks.

3. Raise the lever until it clicks, engage the tabs to the back of thelever and connector, and then securely connect them.

Removal and Installation of Electronic Control Throttle AssemblyREMOVAL1. Remove air cleaner case and air duct.2. Remove harness connector.3. Loosen air horn bolts in turns, and then remove them.4. Loosen injector holder bolts in turns, and then remove them.5. Also loosen chamber bolt of electronic control throttle, and then

remove the chamber. Remove fuel tube.

EFM0095

EFM0096

EFM0097

EFM0098

EF-10

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

207

Removal and Installation of Electronic Control Throttle Assembly (Contd)

INSTALLATIONCaution for installationUniformly tighten bolts diagonally in several steps.CAUTION: Make sure that there is no moisture around connector

when removing and installing throttle position sensor con-nector. Completely wipe off water drops if there are any.

Do not apply voltage to throttle position sensor terminal. Perform "Throttle Valve Closed Position Learning" if dis-

connecting connector. Perform "Throttle Valve Closed Posi-tion Learning and Idle Air Volume Learning" if replacingelectric throttle control actuator.

Do not disassemble electric throttle control actuator.

Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline and Combined Use)PREPARATION Air hose Moving engine harness connector

REMOVAL AND INSTALLATION OF FUEL HOSERemoval Release the fuel pressure. Refer to "Release of Fuel Pressure"

in EC section.

CAUTION:After removal, plug the fuel hose to prevent the fuel fromdraining.

EFM0099

EFM0100

EF-11

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

208

Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline and Combined Use) (Contd)Installation Insert hose until its end reaches 25 mm or more from fuel tube

end. Install a clamp and securely tighten it. Do not install theclamp on top of the bulge.

Start engine, increase the engine speed, and make sure thatthere is no fuel leakage after repairing.

REMOVAL AND INSTALLATION OF FUEL TUBE AND FUEL INJECTORRemoval

CAUTION:Fuel remaining in the tube leaks during operation. Thisoperation should be done in a place free from fire. Remove fuel gallery bolt. Remove fuel gallery. Remove fuel injector and fuel gallery as a

set. Remove clips (4) using long-nose pliers. Disconnect fuel injec-

tor and fuel gallery.

CAUTION:Do not reuse clips.

INSTALLATION OF FUEL INJECTORInstall fuel injector to fuel tube as shown in the figure.Precautions for installation of fuel injector1. Make sure that there is no contamination and damage in O-ring

contact area caused by dirt. Do not clean O-ring with solvent.2. Do not reuse removed O-ring.3. Handle O-ring with bare hands.4. Apply engine oil into O-ring and holder for assembly. (Do not

apply engine oil into fuel passages of fuel injector.)5. Do not use damaged O-ring.6. Do not apply excessive force to damage O-ring.7. Press clips into fuel injector when assembling. Securely fit clips

to fuel injector locating grooves (a) and (b). (Do not reuse clips.)8. Always replace O-ring when clips contact with O-ring.9. Assemble fuel injector to fuel tube after installing clips to fuel

injector.10. Fuel injector is pressed by a force of 196 N (20 kgf) or less. [Stop

operation if a force of 147 N (15 kgf) or more is necessary.]11. Insert fuel injector to fuel tube while aligning fuel tube stopper

(c) with clip cutout (d) before installing. Securely fit (c) to (d) andholder rib (e) to clip hole (f) after inserting.

12. Make sure that fuel injector is securely installed without rotationand disconnection after installing to fuel tube.

EFM0101

EF-12

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

209

Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline and Combined Use) (Contd)FUEL TUBE INSTALLATIONInstall fuel tube to intake manifold as shown in the figure.

Precautions for installation of fuel tube1. Satisfy precautions 1. to 6. for installation of fuel injector.2. Insertion of fuel injector is performed by a force of 196 N (20

kgf) or less. [Stop operation if a force of 147 N (15 kgf) or moreis necessary.]

3. Do not contact O-ring with the edge that is made by eachprocess of intake manifold for assembly.

4. First tighten fuel tube bolt in position a in the figure, and thentighten it in position b in the same figure.

:First tightening: 9.3 - 20.6 Nm (0.9 - 2.1 kgf-m)Second tightening: 20.6 - 26.5 Nm (2.1 - 2.7 kgf-m)

Check for fuel leakage after installationCheck for fuel leakage by racing several times after idling for 5 to 10minutes.

EFM0102

EFM0103

EF-13

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

210

Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline and Combined Use) (Contd)FUEL HOSEInstall fuel hose with the following procedure:1. Tighten clamp in the position that the fuel hose is inserted to the

clamp 1 mm or more (from hose end) while holding hose end asshown in the figure.

2. The inserted length of hose is 28 mm or more.3. Tighten clamp in the position that is 1 mm or more from hose

end with fuel tube assembly installed to engine.4. Make sure that hose winding radius is R70 or more after

installing fuel hose.5. There must be no twisting on the hose after assembling fuel

hose.

6. Difference between pipes (offset) is within 3 mm afterassembling fuel hose.

Precautions for tightening of clampDo not tighten clamp on bulge of fuel tube.(Stop operation if the clamp is placed on the bulge.)

EFM0104

EFM0105

EFM0106

EF-14

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

211

Injector HolderInject the proper amount of fuel supplied from vaporizer based onECM command.

COMPONENT PARTS LOCATIONIt includes mechanical relief valve with LPG injector, LPG assistancesolenoid valve, and fuel pressure sensor.(1) LPG injector

It is used for LPG gas injection.Arrow mark: Fuel flow

(2) LPG assistance solenoid valveEngine output may be insufficient in high-speed and high load area when using LPG injector only. LPG assistance solenoid valve helps LPG injector to keep maximum engine output in high-speed and high load area.

(3) Fuel pressure sensorSends a signal to control fuel injection at low fuel pressure (e.g. in low temperature).

(4) Mechanical relief valveOperates when fuel pressure is over set pressure. It opens fuel circuit, and sends fuel to intake manifold, and protects fuel pip-ing at lower fuel pressure. It is provided in holder fuel passage.

Repair each component specified in (1), (2), (3), and (4) as anassembly if a malfunction is detected in the above components.Refer to EC section for inspection procedure.

EFM0108

EF-15

DISASSEMBLY AND ASSEMBLY OF FUEL SYSTEM

212

VAPORIZER MECHANISM AND OPERATION

Primary (Decompression) RoomThis is decompressed and carbureted high-pressure fuel flow fromLPG tank to approximately 0.3 kgf/cm2.

(1) Primary side valve(2) Primary side valve seat(3) Primary (decompression) room(4) Primary side diaphragm(5) Primary side diaphragm spring(6) Hook (claw)(7) Primary side valve lever

Fuel is supplied from LPG tank to vaporizer via LPG solenoid valve.Fuel from solenoid valve is supplied to primary decompression roomthrough primary side valve (1) and primary side valve seat (2).Fuel pressure supplied to primary room is 0.3 kgf/cm2 or more.Primary diaphragm (4) pushes up diaphragm spring and hook (6)working together. It causes the operation that one side of primaryvalve lever (7) is lifted up. Therefore, the power that pushes primaryvalve (1) toward valve seat side (2) is increased, and fuel flow is cutoff.Primary diaphragm is pushed down by increasing the tension ofdiaphragm spring (5) higher than the fuel pressure when the fuel ofprimary room is consumed and the pressure of primary room insideis decreased to 0.3 kgf/cm2 or less, and hook (6) is working togetherto push primary valve lever (7) down. Therefore, primary valve (1)opens and fuel flows in.Repeat above operations to keep primary room pressureapproximately 0.3 kgf/cm2.

CAUTION:The vaporizer is not field-serviceable. Consult with specializedshop for servicing.

EFM0112

EF-16

VAPORIZER MECHANISM AND OPERATION

213

Primary (Decompression) Room (Contd)Set primary valve lever as shown in the figure.

PRESSURE INSPECTIONCheck primary room pressure with the following procedure:1. Remove primary room test hole plug, and install pressure gage

using appropriate connector.2. Start engine, and check for primary room fuel leakage.

Standard: 0.20 - 0.36 kgf/cm23. Rotate pressure adjusting screw if measured pressure is

outside the standard.

CAUTION:Apply sealant and keep air tightness when reinstalling test holeplug.

IDLE ADJUSTMENT IN ELECTRIC CONTROLLED LPG SPECIFICATIONSIt is not necessary because it is performed with control unit.

IDLE ADJUSTMENT IN CARBURETOR LPG SPECIFICATIONS1. Rotate vaporizer idle adjusting screw so that idle speed is the

highest.2. Adjust idle speed to the specified range using carburetor throttle

adjusting screw.3. Repeat above steps 1. and 2. to set idle speed properly.

REMOVAL OF IMPURITIESLPG includes incombustible materials (e.g. tar).These materials will be collected in vaporizer. This may causeoperating malfunctions of fuel system.It is necessary to periodically release and drain with engine warmedup.

EFM0113

EF-17

VAPORIZER MECHANISM AND OPERATION

214

Primary (Decompression) Room (Contd)DISASSEMBLY, ASSEMBLY, AND INSPECTIONMake sure that there is no leakage from all connections afterassembling all parts.

DISASSEMBLY OF PRIMARY ROOM1. Remove primary cover screw and remove cover.2. Remove primary diaphragm spring.3. Remove primary diaphragm carefully to reverse the direction of

LPG flowing in.4. Remove primary side valve lever as an assembly.5. Remove dust or dirt on all removed parts with dry compressed

air.6. Wipe off sulfurs or tars.7. Assemble in the reverse order of disassembly.

CAUTION: Make sure that diaphragm hook is securely engaged with

the lever. Pulling up the lever (7), blow approximately 4 kgf/cm2 of

compressed air from vaporizer inlet to make sure that pri-mary side valve is placed in the proper position. Replace itwith new one if there is some leakage.

EFM0114

EF-18

VAPORIZER MECHANISM AND OPERATION

215

DescriptionVaporizer has three functions of fuel carburetion, decompression,and conservation of pressure.Vaporizer uses radiator water to prevent vaporizer from freezing bylatent heat of fuel carburetion.

The figure shows vaporizer of carburetor specifications. Electroniccontrolled vaporizer consists of primary room only. PTC heater(electric heating) is integrated for electronic controlled specificationsto help the carburetion when engine starts cold.

EFM0115

VAPORIZER MECHANISM AND OPERATION

EF-19