ch 5 fuel system

8/14/2019 Ch 5 Fuel System

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BASIC FUEL SYSTEM DIAGNOSIS 5-2FUEL LINES AND FllllNGS 5-2FUELLINE FITTINGS 5-2

REMOVAL&INSTALLATION 5-2MULTI-POINT FUEL INJECTION

SYSTEM (MPI) 5-3GENERALINFORMATION5-3FUELSYSTEMSERVICE

PRECAUTIONS 5-3RELIEVING UELSYSTEM

PRESSURE 5-3THROTTLEBODY 5-3

REMOVAL& INSTALLATION 5-3FUELRAILAND INJECTORS(S)5-4REMOVAL&INSTALLATION 5-4TESTING 5-8

FUELPRESSUREREGULATOR -9REMOVAL& INSTALLATION 5-9

PRESSURERELIEFVALVE -9REMOVAL&INSTALLATION 5-9

FUEL TANK 5-10

TANKASSEMBLY 5-10REMOVAL&INSTALLATION 5-10


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I

5-2, FUELSYSTEM

Whenheres a problemtarting r driving vehi- is hereuel? will oftenead o solvingmost asiccle, woof themostmportanthecksnvolvehe g- problems.or gnition ystem iagnosisnd esting,

nition nd he uelsystems.hequestions ostme- pleaseefer o the nformationnengine lectricalchanics ttempto answerirst, is there park? nd componentsnd gnition ystemsound arliern

thismanual.f the gnition ystemhecks ut thereis spark),hen oumust eterminef the uelsystem

is operatingroperlyis hereuel?).

REMOVAL&INSTALLATION

# See Figures 1 thru 7

The uel ines sed nall modelsovered y hismanualrequite traightorward. ypicallyhe it-tings reeither ubber oses onnectingo steelineswithclamps,r steelines onnectingo steelinesusing etaining oltsor lare ittings. everalittingsareunique uch s hebanjo-boltittingon he uelfeed ine rom he uel ilter.

ventitateuarea. Do not allow fuel spray orvapors o come n contactwith a spark orooen flame. Keena drv chemical ire extin-

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system, always work in a well___ . . _

guisher near thework &ea. Always keep uelin a containerspecifically designed or fuelstorage;also, always pmperly seal fuel con-tainers to avoid the possibility of fire or ex-plosion.

Fig. 1 This photo of the fuel pump ines isan example of the type of fittings found onmost models.The return ine utilizes a rub-ber hose and a hose clamp, while the feedline utilizes a flare fitting

Fig. 2 This fitting on the fuel pressure reg-ulator utilizes a rubber hose and a hoseclamp. Remove he hose clamp . . .


3/16

FUELSYSTEM 13

l Alwayseplace orn uel ittingO-rings ithnew.Donotsubstituteuelhose r equivalent,here I

TheMulti-PointnjectionMPI) ystems electroni-rally controlledy heEngine ontrolModuleECM),based ndatarom arious ensors.heECM ontrolsthe uel low, dle peed nd gnitioniming.

fuelpipe s nstalled.

Fuels suppliedo he njectorsyanelectricn-tankuelpump nd s distributedo he espectiven-jectors ia hemainuelpipe. he uelpressurep-pliedo he njectors constantndhigherhanhepressuren he ntake anifold.he ressures con-trolled y he uelpressureegulator.he xcessuel

is returnedo he uel ankhroughhe uel eturn ipe.When nelectric urrentlows n he njector,heinjector alve s fullyopenedo supplyuel.Sincehefuelpressures constant,heamount f he uel n-jetted rom he njectornto hemanifolds ncreasedor decreasedn proportiono he ime heelectriccurrentlows.Based n ECU ignals,he njectorsn-ject uel o thecylindermanifold orts n firingorder.

Fuel injection systems emain under pres-sure after the engine has been urned OFF.Properly relieve fuel pressurebefore discon-neetingany fuel lines. Failure to do so mayresult in fire or personal njury.

1. Turn he gnitiono heOFFposition.2. Loosenhe uel iller cap o releaseuel ank

pressure.

IThelow rate f theair drawnhroughheair

cleaners measuredy heair lowsensor. he ir

entersheair ntake lenumr manifoldhroughhethrottle ody. n he ntakemanifold,heair s mixedwith he uel rom he njectorsnd s drawnnto hecylinder, he ir low ate s controlledccordingothedegree f the hrottle alve nd heservomotoropenings.he ystems monitoredhrough num-berof sensors hicheed nformationnengine on-ditions nd equirementso theECM. heECM al-culateshe njectionime nd ate ccordingo hesignalsrom hesensors,

Safetys themostmportantactorwhen erform-ingnotonly uelsystem aintenanceutany ypeofmaintenance.ailureo conduct aintenancend e-pairs n a safemanner ay esultn serious ersonalinjury r death.Maintenancend esting f thevehi-cles uelsystem omponentsanbeaccomplished

f l d ff i l dh i h ll i

Observe ll applicablesafety precautionswhenworkingaround uel. Whenever ervic-

ing the fuel system,always work in a wellventilatedarea. Do not allow fuel sprayor va-pors o come n contactwith a sparkor openflame. Keepa dry chemical ire extinguishernear he work area. Alwayskeep uel in a con-tainer specifically designed or fuel storage;also, always properlyseal fuel containers oavoid he possibility of fire or explosion.

3. For heMirage, iamante,nd1994-00

Galant,emovehe ear eat ushion,hen emovetheservice over nddetachhe uelpump arnessconnector.

4. For he1990-93 WDGalant,etachhe uelpump arnessonnectorocatedn hearea f thefuel ank. t may enecessaryo raisehevehicleoaccessheconnector.

5. For he1990-93 WDGalant,emovehecar-pet rom he runk,ocatehe uel ankwiringat he

h hh i i

Fig, 8 Detach he connector or the throttleposition (TP) sensor

93153ps5

Fig, 9 Remove the accelerator cable endfrom the throttle lever


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5-4 FUELSYSTEM

93155422

Fig. 12 Explodedview of the throttle bodyand related components-l .5L engine

15-Z Nm11-16 lt.lbs.

15-22 Nm11-16 ft.lbr.

1. Connectnn for accelerator cable

2. Connection for breather hose3 Connection for au intake hose4 Connectton for au hose C5. Connectton for vacuum hose6 Connectton for IAC motor connector and

closed throttle posItIon swtch connector7 ConnectIon for TPS connector8 Connectton for water hose9 Connectnon for water by-pass hose

10 Ground plate mounting screw11. Throttle body stay and ground plate12 Au flttlng13 Gasket14 Throttle body15 Gasket

89575422

:ig. 14 Exploded iew of the throttle body and related components-l.61 and 2.OLDOHC n-line


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FUELSYSTEM5-5,21. Connect he negativebatterycable.Refill he

cooling system.

REMOVAL& INSTALLATION

1.5L, 1.8L, And 2.OLSOHCEngines

ti See Figures 17, 18, and 19

1. Relieve he uel systempressure s describedin this section.

2. Disconnect he PCV hose rom the valve

cover. Also disconnecthe breather oseat the oppo-site end of the valve cover.3. Remove he bolts holding he high pressure

fuel line o the uel rail and disconnect he line. Beprepared o contain uel spillage;plug he ine okeepout dirt and debris.

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system,always work in a wellventilated area. 00 not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guisher near he work area. Always keep uelin a containerspecifically designed or fuelstorage;also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-plosion.

4. Remove he vacuumhose rom the uel pres-sure regulator.

5. Disconnect he uel returnhose rom thepressure egulator.

6. Labeland detach he electricalconnectorsfrom each njector.

7. Remove he bolt(s) holding he uel rail to themanifold.Carefully ift the rail up and remove t withthe injectorsattached. akegreatcare not o drop an

1Hilt4naunfu(norc e Fu(l:E%!,,.,.- 1: IEE: Efgz tz!z? :: %%I;P&.xmeaw 13m

Fig. 17 Explodedview of the fuel injectors and related components-l .5L engine


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installhe ine o he uel ail.Tightenhemountingbolts,

19. AttachhePCV ose nd hebreatherosefthevwere isconnected.

20. Connecthenegativeatteryable. ressur-

ize he uelsystem nd nspect ll connectionsor Ileaks.

1.6L and 2.01 DOHCEngines

b See Figure 20

1. Relievehe uelsystem ressuresdescribedin hissection.

2. Disconnecthenegativeattery able.3. Wrapheconnectionitha shopowel nd

disconnecthehighpressureuel ineat he uel ail.

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing he fuel system,always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guisher near he work area. Always keep uelin a containerspecifically designed or fuelstorage; also, always properly seal fuel con-

* tainers to avoid the possibility of fire or ex-plosion.

4. Disconnecthe uel eturn ose nd emovetheO-ring.

5. Disconnecthevacuumoserom he uelpressureegulator.

6. DisconnecthePCV ose.On2.OL ngine,removehecenter over.

1 x Connection for PCV hose2. Connection for high pressure fuel hose3. O-ring4. Connection for vacuum hose5. Connection for fuel return hose&2 I=,1c.1 rncc*.ra regu,ator

lble clamD

7. Label nddetachheelectricalonnectorsfromeachniector.

8. Accelerator ca9. Center cover

.

10. Connection for control harness11 Fuel rail12. Insulator13. Insulator14. Injector15. O-ring16. Grommet

89575g27

Explodedview of the fuel injectors and relatedcomponents 1.6L and 2.QLDOHC

5-6 FUELSYSTEM

8. Removehe njectorail retaining olts,Makesure he ubbermountingushingso notget ost.

9. Lift he ailassemblypandawayrom heengine.

10. Removehe njectorsrom he ail bypullinggently iscardheowernsulator heckhe esis-


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FUELSYSTEM -7

Fig, 25 Remove he vacuum hose from the Fig. 25 Detach he connectors rom all of

pressure regulator the fuel injectors

1H; :A ..;lt;;aft~rgi,i~;yl the ;F: 1 / . 93155p15ig 29 Remove he fuel injectors from thetall by gently rocking hem loose

Fig. 27 Remove he two fuel rail retaining

bolts . . .

93155ps

Fig. 30 Always replace the O-rings on theinjectors before reinstalling them

1. Relievehe uelsystem ressuresdescribedin hissection.2. Label nddisconnecthespark lugwires.

Positionhewiresaside.3. DisconnecthePCV oserom hevalve

cover,4. Removeheboltsholdinghehighpressure

fuel ine o he uel ail, hen isconnecthe ine.Bepreparedo containuelspillage; lug he ine o

on heworkbench;rotecthe ipsof he njectorsfromdirtand/ormpact.9. Removenddiscardhe njectornsulators

from he ntakemanifold.he nsulatorsrenotreusable.

10. Removehe njectorsrompulling entlyn a straight utwarc

the uel ailbyI motion. ake er-

tain hegrommetndO-ring ome ffwith he njector.

18. Connecthe uel eturn oseo hepressureregulator,hen onnecthevacuumose.19. ReplaceheO-ring n hehighpressureuel

line, oat heO-ringightlywithclean,hinoil andinstallhe ine o he uel ail.Tiahtenhemountina

To install:

-

the uel ystemnd nspectll connectionsor eaks.

bolts o 4 ft. bs. 6 Nm).20. ConnecthePCV ose nd park lugwires.21. Connecthenegativeatteryable. ressurize


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5-8 FUELSYSTEM

9 ,npimr w1m.m

1: iL,

1: 82w93155gx

Fig. 31 Exploded iew of the fuel injectors and related components-s.OLengines

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system,always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-

guisher near he work area. Always keep uelin a containerspecifically designed or fuelstorage; also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-plosion.

6. Disconnect he uel returnhoseand removethe O-ring.

7. Disconnect he vacuumhose rom the uel

Fig. 32 Exploded iew of the fuel injectors and related components-3.5L engine

17. Connect he uel returnhose.18. Replacehe O-ring, ightly ubricate t and

connect he high pressure uel ine.19. Usmgnew gaskets, nstall he ntakeplenum

and all related tems. Refer o Section3.20. Fill the cooling system.21. Connect he negativebattery ableand check

the entiresystem or properoperationand eaks.

The easiestway o test he operationof the uel in-jectors s to listen or a clicking soundcoming romthe injectorswhile he engine S running.This is ac-complishedusinga mechanics tethoscope, r along screwdriver.Place he end of the stethoscope rthe screwdriver tip end, not handle)onto he bodyofh j Pl h i f h h

cylinder causes he least difference n the idle.The one that causes he least change s the weakcylinder.

If the njectorswereall clicking and he gnitionsystem s functioningproperly, emove he njectorofthe suspectcylinderand bench est t. This is accom-plishedby checking or a spraypattern rom the in-jector itself Installa fuel supply ine o the njector(or rail if the njector s left attachedo the rail) andmomentarilyapply12 volts DC anda ground o theinjector tself;a visible fuel sprayshouldappear. f nospray s achieved, eplace he injectorand check herunningcondition of the engine.

One or More InjectorsAre Not Clicking

6 See Figures 33, 34 , 35, and 36


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\ FUELSYSTEM -9

p See Figures 37, 38, 39, 49, and 41

REMOVAL&NSTALLATION

1. Properlyelievehe uelsystem ressuresoutlined arliern hissection.

2. Removehevacuumose rom he uelpres-sure egulator.

3. Disconnecthe uel eturn oserom hepressureegulator.

Fig. 33 Unplug he fuel injector connector,

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system, always work in a wellventilated area. Do not apow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guishernear he work area. Always keep uelin a containerspecifically designed or fuelstorage; also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-

plosion.

I

,~*I.. ..-.. * . .. ._. . -...

To install:IFig. 36 If the correct noid light flasheswhile the engine s running, he injector dri-ver circuit inside the PCM s working

5. ReplaceheO-ring n uelpressureegulatorwitha newoneand oat t lightlywithclean,hinoil.

6. Inserthe egulatortraightnto he ail, henchl . . . * * . . , .xk matn canoe orareareery.

4. Removehe uel egulatoretainer oltsor re-movehe etainingnapring,hen emovehe uelrrwkdnr frnm the fl~el rail

91055pu2

Fig. 35 Plug he correct noid light directlyinto the iniector harness connector

I I I ,

r, If it does not rotate smoothly, remove tand nspect he O-ring or deformationordamage.

7. When roperlynstalled,lign hemountingholes.f equipped,nstall nd ightenhe etainingbolts o 8 t. Ibs. 11Nm). f equipped,nstallhe eg-ulator etainingnapring.

8. Connecthe uel eturn oseo hepressureregulator


10/16

5-10 FUELSYSTEM1. _Fuel tank pressure

- relef vdive\


p See Figures42 and 431. Raiseand safelysupport he vehiclesecurely

on ackstands.2. Remove he hosesand remove he pressure e-

lief valve.3. The nstallation s the reverseof removal.

c, Always nstall the pressure elief valvewith the arrow pointing oward he EVAP an-ister side, not the fuel tank

1mame shown, others similar g3155gFig 42 Pressure elief valve location-llia

I IEvaporatwe emlssloncanister side

Tank side

+k93155gt7

Fig. 43 Always install the pressure reliefvalve with the arrow pointing toward theEVAP anister side, not the fuel tank


p See Figures44 thru 581. Properly elieve he uel systempressureus-

ing properprocedures.2. Disconnect he negativebattery able.3. Raise he vehicleand supportsafelv.4. Drain he uel rom the uel ank nto anap-

provedcontainer.

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system, always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guishernear he work area. Always keep uelin a containerspecifically designed or fuelstorage; also, always properly seal fuel con-

5. On Diamantemodels:a. Remove he left rear wheel well liner.b Disconnect he centerexhaustsystem rom

the main muffler.Disconnect he rear exhausthangers, ower he exhaustand secureaside.

c. On modelsequippedwith 4-wheel steering,remove he mountingbolts and lower the rearsteeringgear.

6. Disconnect he returnhose,high pressurehoseand vapor hoses rom the uel pump.

7. Detach he electricalconnectors t thepump/sending nit.

8. Disconnect he iller and vent hoses. s9. Placea suitable ack under he centerof the

fuel ankand applya slight upwardpressure.Removethe uel ank strap retainingnuts.

10. Lower he ank slightly and detachany re-mainingelectricalor hose connectors t the uel ank.

11. Remove he uel ank rom the vehicle.To install:12. If replacing he ank, ransferany necessary

componentso the new ank ncludingany heatshields,hoses,valves,and he uel pump.

13. Install he uel ankonto he ack. Rarsehe

clearanceo attach he electricaland hoseconnec-tions to the op of the uel pump.

14. Attachall connectronso the op of the ank.15. Raise he ank completelyand position he re-

tainer strapsaround he uel ank. nstall new ueltank self-lockingnutsand ighten he nuts.

16. Connect he returnhoseand high pressurehoses.

17. Install he vapor hoseand he iller hose. n-stall he iller hose retainer crews o the ender, f re-moved.

18. On Diamantemodels:a. If equippedwith 4-wheel steering, nstall

the power cylinder unit and ighten he mountingbolts o 31 ft. Ibs. (43 Nm).

b. Connect he exhaustpipe and secure herear hangers.

c. Install he left rear wheel well liner, if re-moved.19. Lower he vehicleand pour he drained uel

into the gas ank.20. Connect he negativebattery able.Check he

fuel pump or properpressure nd nspect he entiresystem or leaks


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FUELSYSTEM -11

93155gZi

Fig. 46 Fuel tank and related components exploded view-1997-98Mirage

Vapor hose

Fig. 47 Fuel tank and related components exploded view-1999-00

5 12 FUELSYSTEM


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5-12 FUELSYSTEM

Fig. 50 Fuel tank and related components-1990-93 AWDGalant


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FUELSYSTiM 5-13

1. BODY HARNESS CONNECTION2 HOSE CONNECTION3 PURGE HOSE4 VAPOR HOSE5 VENT HOSE6 FllLER HOSE7 PIPE ASSEMBLY8. BAND ASSEMBLY9 FUEL TANK ASSEMBLY

10. DIFFERENTIAL PRESSURESENSOR

11 FUEL HARNESS12 HIGH-PRESSURE FUEL HOSE

1; ;;JL RETURN HOSE

15 FUEL PUMP MODULE16 FILLER NECK17 FUEL CAPIS REINFORCEMENT19 PACKING20 VAPOR HOSE21 SEPARATOR ASSEMBLY22 VAPOR HOSE

23 FUEL CHECK VALV E ASSEMBLY24 FUEL FILLER NECK ASS EMBLY

Fig. 54 Fuel tank and related components-1999-00 Galant :ia. 55 Fuel tank and related components-1992-96 Diamante

7923PG79

:ig. 57 Proper method of supporting real

.


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5-14 FUELSYSTEM

93155(10:

ig. 59 loosen self-locking nuts on tank

mpporf straps to the end of the stud bolts-1990-93 FWDGalant

9355Qo$

:ig. 60 Remove he six retaining bolts andlasket from the base of the tank-1990-93:WD Galant

Qm

0a

a-a al2 0

0Q a a

ALL WHEEL DRIVE (A WO)

# See Figures 62, 63, and 64

1. Relieve he uel systempressureusing properprocedure.

2. Disconnect egativebattery able.3. The uel pump s located n the uel ank. Re-

move he access cover ocated n the rear loor pan4 Parballydrain he uel ank nto an approved

gasolinecontainer.

Observeall applicable safety precautionswhen workina around uel. Whenever ervic-ing the fuel system,always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guisher near he work area. Always keep uelin a containerspecifically designed or fuel

-ig. 62 The uel pump s located in the fuel

rnk. Remove he access cover located m

he rear floor pan -1990-93 AWDGalant

storage; also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-plosion.

5 Remove he electricalconnector rom he uel

pump.6. Remove he overfill limiter (two-wayvalve),as required.

7. Remove he high pressure uel hose connec-tor.

8. Remove he six pump retamingbolts and re-move he uel pumpand gaugeassembly rom thetank. Note positioningof pumpprior to removal romtank.

To install:

*If the packingmaterial is damaged r de-formed, replace t with new packing.9. Align the 3 projectionson the packingwith

the holes on the uel pumpand he nippleson thepump acmg he samedirectionas before emoval.Install he retainers nd lghten o 2 ft. Ibs. (3 Nm).

10. Install he high pressurehoseconnectionandtighten o 29 ft. Ibs. (40 Nm).

11. Install he overfill limiter (two-wayvalve) andthe electricalconnector o the uel pump.

12. Fill the uel ankwith the gasoline emovedduring his procedure.

13. Reconnecthe negativebatterycableandcheck he entire system or leaks.

14. Install3M ATD Part No. 8625 or equivalent,to the rear loor panand nstall he accesscover ntoplace.

Diamante,1993-00 Mirage, and 1994-98Galant

# See Figures 65 thru 72

1. Properly elieve he uel systempressure.2. Disconnect he negativebattery able.3. Remove he rearseat cushion,by pulling he

seat stopperoutwardand ifting he ower cushionupward.

4. Remove he accesscover.5 Di th l i i


15/16

FUELSYSTEM -15*Tilt the float to the left of the vehicle, wheninstalling he pumpassembly..

10. Connecthehighpressureose, eturn oseand he uel ankwiring.

11. Connecthenegativeattery able.12. Checkhe uelpumpor proper ressurend

\ inspectheentire ystemor eaks.13. Apply ealanto heaccess over nd nstall

thecover.14. Installhe ear eat ushion.

1999-M Galant

b See Figures65 thru 75

1. Properlyelievehe uelsystem ressure.2. Disconnecthenegativeatteryable.3. Removehe ear eat ushion, y pullinghe

seat topper utward nd ifting he ower ushionupward.

4. Removeheaccess over.

Fig. 73 Using special tool MB991480or1equivalert, remove he fuel pump etaining

.


16/16

5-16 FUELSYSTEM6. Disconnect he returnhose and he high

pressure uel hose.7. Using special ool MB991480 or equivalent,

remove he uel pump etainingcap and remove hepumpassembly.

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system,always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guisher near he work area. Always keep uelin a containerspecifically designed or fuelstorage;also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-plosion.

To install:*If the packingmaterial is damaged r de-formed, replace t with new packing.

8. Install he packing o the uel ank.9. Install he ue l pumpassembly o the ank

and align he matingmarkson the pumpand hefloorpan.

10. Tighten he uel pump etainingcap usingtool MB991480 or equrvalent.

11. Connect he high pressurehose, eturnhoseand he uel ankwirmg.

12. Connect he negativebatterycable.13. Check he ue l pump or properpressureand

inspect he entiresystem or leaks.14. Apply sealant o the accesscover and nstall

the cover.15. Install he rearseat cushion.

TESTING

1. Relieve uel systempressure.2. Disconnect he batterynegative able.3. Disconnecthe uel hrghpressurehoseat he

deliverypipe side.

Observeall applicable safety precautionswhen working around uel. Whenever ervic-ing the fuel system, always work in a wellventilated area. Do not allow fuel spray orvapors o come n contactwith a spark oropen lame. Keepa dry chemical ire extin-guisher near he work area. Always keep uelin a containerspecifically designed or fuelstorage;also, always properly seal fuel con-tainers to avoid the possibility of fire or ex-alosion.

4. Connecta fuel pressure auge o toolsMD998709 and MD998742 or exactequivalent,withappropriate dapters, ealsand/or gaskets o preventleaksduring he est. nstall he gaugeand adapterbetweenhe deliverypipe and high pressurehose. n-stall carefully o prevent eaks.

5. Connect he negativebattery able.6. Apply battery oltage o the erminal or fuel

pumpactivation located n the enginecompartment)to run he uel pump,andcheck or leaks.

7. Start he engineand run at curb dle speed.8. Measure he uel pressure nd compare o

the specifications isted n the chart n Section1.9. Locateand disconnect he vacuumhose run-

ning o the uel pressure egulator.Plug he end of

the hoseand record he uel pressure gain.The uelpressure hould have ncreased pproximately Opsi.

10. Reconnecthe vacuumhose he uel pressureregulator.After he uel pressure tabilizes, ace heengine2-3 times and check hat he uel pressuredoes not all when he engine s runningat idle.

il. Check o be sure here s fuel pressure n thereturnhose by gentlypressing he uel returnhosewith fingerswhile racing he engine.Therewill be nofuel pressure n the returnhosewhen he volumeoffuel low is low.

12. If fuel pressure s too low, check or aclogged uel ilter, a defective uel pressure egulatoror a defective uel pump,any of which will require e-placement.

13. If fuel pressure s too high, he uel pressureregulator s defective nd will have o be replaced r

the uel return s bentor clogged. f the uel pressurereadmgdoesnot changewhen he vacuumhose sdisconnected,he hose s cloggedor the valve sstuck n the uel pressure egulator nd t will have obe replaced.

14. Stop he engineand check or changes n thefuel pressure auge. t should not drop. f the gaugereadingdoesdrop, watch he rate of drop. If fuelpressure rops slowly, he ikely cause s a leakinginjectorwhich will require eplacement.f the uel

pressure rops mmediately fter he engine sstopped, he checkvalve n the uel pump snt clos-ing and he uel pumpwill have o be replaced.

15. Relieve uel systempressure.16. Disconnecthe high pressurehoseand re-

move he uel pressure auge rom the deliverypipe.17. Installa new O-ring n the groove of the high

pressurehose.Connect he hose o the deliverypipeand ighten he screws.After nstallation, pplybat-tery voltage o the erminal or fuel pumpactivation orun he uel pump.Check or leaks.

ch 5 fuel system

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