4-14 Chapter 4 Fuel and exhaust systems

15 Fuel filter - removal andinstallation

Warning: Gasoline is extremely flammable,so take extra precautions when you work onany part of the fuel system (see the Warningin Section 2).

RemovalRefer to illustration. 15.11 The in-line fuel filter mounts to the frameabove the rear of the fuel tank, near the fillerneck (see illustration).2 Remove the fuel tank filler cap to relievefuel tank pressure.3 Perform the fuel pressure relief proce-dure (see Section 2).4 Disconnect the negative battery cablefrom the ground stud on the left shock tower(see Chapter 5, Section 1).5 Working inside the trunk, fold back thetrunk mat near the base of the left shocktower. Locate the fuel pump wiring harness4-pin connector and disconnect it from thewiring harness (see illustration 2.3). Followthe fuel pump wiring to the grommet at thebase of the rear seat. Tie a length of string tothe fuel pump wiring harness and secure theother end somewhere in the trunk (this willallow you to easily retrieve the wiring har-ness). Push the grommet through the floor-pan and feed the wiring and 4 pin connectorthrough the hole.6 Raise the vehicle and support it securelyon jackstands.7 Position an approved gasoline containerunder the fuel tank drain plug. If necessary,use a funnel to prevent spilling fuel. Warning:The fuel tank capacity is 16 gallons. Unlessthe fuel tank is almost empty, be prepared tocollect a significant amount of fuel. Do notleave the fuel tank draining operation unat-tended. Be prepared to replace the drain plugin case the fuel tank capacity exceeds thecontainer capacity. Remove the drain plug(see illustration 5.6) and drain the fuel intothe container.8 After the fuel has finished draining, rein-stall the drain plug and tighten it to the torqueli sted in this Chapter's Specifications.9 Support the fuel tank with a floor jack.Place a piece of wood between the jack headand the fuel tank to protect the tank.10 Remove the driver's side fuel tank strap(the long strap).11 Loosen, but do not remove, the passen-ger side fuel tank strap so the fuel tank fillerneck just touches the rear suspension cross-member. Caution: Do not let the weight ofthe fuel tank rest on the filler neck! Support itwith the jack at all times.12 Label and disconnect the quick-connectfuel line fittings (see Section 4 if necessary)connecting the fuel filter to the fuel system.13 Detach the fuel filter from its mountingand remove it from the vehicle.

Installation14 Installation is the reverse of removal.

15.1 The fuel filter (arrow) is tucked upbehind the fuel tank and mounted to

the frame above the rearsuspension crossmember

15 Assemble the fuel line quick-connect fit-tings as described in Section 4. Verify the fit-tings are securely assembled by trying to pullthem apart. Note: The fuel filter larger line fit-ting attaches to the fuel pump module "sup-ply" port and the smaller fitting attaches tothe "return" port.16 Tighten the fuel tank strap bolts to thetorque given in this Chapter's Specifications.17 Pressurize the system and check forleaks.

16 Fuel rail and injectors - check,removal and installation

Warning: Gasoline is extremely flammable,so take extra precautions when you work onany part of the fuel system (see the Warningin Section 2).

Fuel injector operation checkRefer to illustrations 16.6 and 16.71 Start the engine and allow it warm up tonormal operating temperature.2 Remove the air cleaner assembly (seeSection 9).3 If the vehicle is not equipped with atachometer, connect one to the engine inaccordance with the tool manufacturer'sinstructions.4 Make sure all test equipment is posi-tioned away from the drivebelts and coolingfans, then start the engine. With the engineidling, detach each fuel injector electricalconnector one-at-a-time, and note the rpmchange on the tachometer, then reconnectthe injector. Note: On V6 engines, this testcan only be applied to the left bank of fuelinjectors and only after removing the air inletresonator (see Section 9). If the rpm changeis approximately the same for each cylinder,the injectors are operating correctly. If dis-connecting a particular injector fails to

16.6 Measure the resistance of eachinjector. It should be approximately

12 ohms

change the engine rpm, proceed to the nextStep. If the fuel injectors are operating prop-erly, check the ignition system (see Chap-ter 5), condition of the spark plugs and wires(see Chapter 1) and, if necessary, perform acompression check (see Chapter 2C) todetermine the cause of the dead cylinder.5 On V6 engines, remove the upper intakemanifold (see Chapter 2B).6 Disconnect the injector electrical con-nectors and using an ohmmeter, measure theresistance of each injector (see illustration).Compare the measured resistance to thevalue given this Chapter's Specifications. Ifthe resistance is not within specifications,replace the injector.7 If the resistance is as specified, connecta special injector harness test light (com-monly known as a "noid light" which is avail-able at most auto parts stores) to the injectorelectrical connector (see illustration). If theli ght flashes, the injector is receiving voltage.If there is no voltage, check the ASD relayoperation (see Section 3). If the ASD relay isOK, check the injector wiring circuit for ashort, a break in the wire or a bad connection(see Chapter 12 if necessary).8 With the electrical connector removedfrom the injector, use a fused jumper wire toconnect one terminal of the injector to thepositive remote terminal of the battery nearthe Power Distribution Center (PDC). Attachanother jumper wire to the other terminal onthe fuel injector. Make sure the jumper wiresare properly insulated from each other! Usingthe grounded jumper wire, quickly connectand disconnect it to a solid ground on theengine. Note: Do not subject the fuel injectorto battery voltage any longer than necessary.Each time the injector is energized and de-energized, the injector should make an audi-ble "clicking" sound. If no sound is heard.replace the injector. Repeat the test for eachinjector.9 If the fuel injectors are operating prop-erly, install all removed components in thereverse order of removal.