FUEL SYSTEM. Table of Contents. Section 3D - Fuel Injection. Specifications... 3D-2 Special Tools... 3D-3

Transcription

1 Tle of Contents FUEL SYSTEM Section 3D - Fuel Injection FUEL INJECTION Specifictions D-2 Specil Tools D-3 Notes: D-6 Air Temperture Sensor/Throttle Position Sensor. 3D-7 ECM Assemly D-8 Fuel Mngement System D-10 Fuel Pump D-14 Electronic Fuel Injection (EFl) System D-16 Introduction D-16 Using the Test Procedures D-16 EFI System Tests D-16 Sfety Precutions D-16 Fuel Injection System Function D-17 Preliminry Checks D-17 Ignition Sprk Check D-17 Electronic Fuel Injection Set Up D-18 Fresh Qulity Fuel D-18 Low Bttery Voltge D-18 Fuel Flow Digrm D-19 Fuel Flow Component Description D-20 Electric Fuel Pump D-20 Pulse Fuel Pump D-20 Wter Seprting Filter D-20 Vpor Seprtor D-20 Bleed System D-20 Finl Filter D-20 Electric Fuel Pump (Inside Vpor Seprtor). 3D-20 Fuel Injectors D-21 Induction Mnifold D-21 Fuel Pressure Regultor D-21 EFI Electricl Components D-21 EFI Fuel Mngement (Low Pressure Route)... 3D-24 EFI Fuel Mngement (High Pressure Route)... 3D-25 Fuel Ril Electricl/Fuel Determintion D-26 EFI System Test Procedures D-27 Fuel Guge Connection/Pressure Test D-27 Vpor Seprtor Fuel Delivery Test D-28 Vpor Seprtor Flot Test D-29 Wter Seprting Filter Flow Test D-30 Electric Fuel Pump Delivery Test D-31 Finl Filter Check nd De-pressurizing EFI System Procedures D-32 Pressure Regultor Test D-34 Electric Fuel Pump Voltge Test D-36 Injector Electricl Hrness Test D-39 ECM Injector Driver Test D-40 Injector Fuel Delivery Test D-40 Injector Opertion Test D-40 Induction Mnifold Lek Check D-42 Air Temperture Sensor Test D-44 Engine Hed Temperture Sensor Test D-45 Throttle Position Sensor Test D-46 Mp Sensor Test D-47 Prolem Dignosis D-48 Engine Hed Temperture Sensor Removl.... 3D-51 EFI Induction Mnifold Removl D-51 Wter Seprting Filter Assemly Removl.. 3D-53 Wter Seprting Filter Assemly Instlltion 3D-54 Throttle Position Sensor/Temperture Sensor/ Fuel Injector Hrness Disconnections D-54 Oil Reservoir Removl D-56 Fuel Pressure Regultor Removl D-57 Fuel Pressure Regultor Disssemly D-58 Fuel Pressure Regultor Ressemly D-58 Vpor Seprtor Removl D-59 Vpor Seprtor Disssemly D-61 Instlling Vpor Seprtor Assemly to Induction Mnifold D-67 Mnifold Removl D-70 EFI Induction Mnifold Disssemly D-72 Air Temperture Sensor Removl D-72 Throttle Position Sensor Removl D-73 Fuel Ril Removl D-74 Fuel Ril Disssemly D-76 Fuel Injector Removl nd Disssemly D-76 Injector Hrness Removl D-78 Throttle Linkge Removed D-79 EFI System Clening nd Inspection D-80 Induction Mnifold Assemly D-81 Injector Hrness Instlltion D-81 Fuel Injector Assemly nd Instlltion D-82 Fuel Ril Assemly D-84 Fuel Ril Instlltion D-84 Throttle Position Sensor Instlltion D-86 Air Temperture Sensor Instlltion D-87 EFI Induction Mnifold Instlltion D-89 Oil Reservoir Instlltion D-91 Vpor Seprtor Instlltion D-92 Throttle Position Sensor/Temperture Sensor/ Fuel Injector Hrness Connections D-94 ECM Instlltion D-95 Engine Hed Temperture Sensor Instlltion 3D-97 3 D NOVEMBER 1999 Pge 3D-1

2 Specifictions Electronic Fuel Injection Idle RPM All Models Wide Open Throttle RPM Flot Adjustment (Vpor Seprtor) Flot Level Fctory Fuel Injectors All Models (Quntity) Ignition Controller Uses the Trigger Signl s n Injector Timing Signl s follows: #1 Trigger Circuit #3 Trigger Circuit #5 Trigger Circuit Line Injectors 6 #3 nd #4 Injectors #5 nd #6 Injectors #1 nd #2 Injectors 34 psi 36 psi (234kP 248kP) Pge 3D NOVEMBER 1999

3 Specil Tools FUEL INJECTION 1. Fuel Pressure Guge A7 () or Fuel Pressure Guge A3() Digitl Dignostic Terminl (DDT) T2 3. Softwre Crtridge DDT Reference Mnul NOVEMBER 1999 Pge 3D-3

4 5. Adptor Hrness A5 (use with DDT) 6. Remote Strter Switch A1 7. DMT 2000 Digitl Tchometer Multi-meter P/N A1 8. Inductive Timing Light Sprk Gp Tester T Pge 3D NOVEMBER 1999

5 10. Injector Test Hrness A1. Cn e used to verify tht the ECM is supplying operting voltge to the injectors. Hrness is connected etween the injector hrness nd the engine hrness. Hrness is used in conjunction with DVA meter A1. Hrness will lso serve s convenient wy to connect the injector hrness to perform injector resistnce test. c d e f -To Injector Mnifold -To Engine Hrness c -RED 11. Sprk Plug Wire Extension (6e) A1) d-white e -BLUE f -YELLOW 12. Strp Wrench A NOVEMBER 1999 Pge 3D-5

6 Notes: Pge 3D NOVEMBER 1999

7 Detontion Controller/Air Temperture Sensor/Throttle Position Sensor FUEL INJECTION TORQUE REF. NO. QTY. DESCRIPTION l. in. l. ft. N m 1 1 RPM LIMITER 2 3 SCREW SCREW Drive Tight 4 1 BUSHING 5 3 IGNITION CONTROL MODULE 6 1 INDICATOR throttle position 7 2 SCREW LOCKWASHER 9 2 WASHER 10 1 SLEEVE 11 2 PLATE 12 1 AIR TEMPERATURE SENSOR ASSEMBLY 13 1 O-RING 14 3 SCREW Drive Tight 15 3 LOCKWASHER NOVEMBER 1999 Pge 3D-7

8 ECM Assemly Dielectric Grese ( ) Liquid Neoprene ( ) Pge 3D NOVEMBER 1999

9 ECM Assemly TORQUE REF. NO. QTY. DESCRIPTION l-in l-ft Nm. 1 E.C.U. ASSEMBLY (150) 1 1 E.C.U. ASSEMBLY (175) 1 E.C.U. ASSEMBLY (200) 2 2 SPACER 3 1 CLIP 4 2 MOUNT cowl mounting rcket 5 4 WASHER 6 4 NUT CABLE ASSEMBLY 8 1 GROMMET 9 1 BUSHING 10 1 SCREW (1/4-20 x 1) LOCKWASHER 12 1 WASHER 13 1 WATER SENSOR MODULE ASSEMBLY 14 2 SCREW (3/16-32 x 1/2) WASHER 16 1 CONNECTOR (SERVICE) 17 AR STA STRAP NOVEMBER 1999 Pge 3D-9

10 Fuel Mngement System Pge 3D NOVEMBER 1999

11 Fuel Mngement System TORQUE REF. NO. QTY. DESCRIPTION l-in l-ft Nm. 1 FUEL MANAGEMENT ASSEMBLY 1 1 COVER 2 1 HARNESS KIT 3 1 SEAL 4 1 O RING/SEAL KIT 5 1 FUEL RAIL 6 1 FUEL INJECTOR 7 1 FILTER 8 1 RETAINING KIT 9 1 THROTTLE BODY 10 1 JOINT KIT 11 1 LINK 12 1 LINK LEVER KIT 13 1 STOP SCREW KIT 14 1 SCREW KIT ELBOW KIT 16 1 SCHRADER VALVE KIT 17 1 FMA JOINT KIT 18 1 HOSE KIT 19 1 ROLLER SCREW (1/4-20 x 4 IN.) WASHER 22 1 TEMPERATURE SENSOR ASSEMBLY 23 1 O-RING 24 3 SCREW (8-32 x 3/8) Drive Tight 25 3 LOCKWASHER 26 1 INDICATOR throttle position 27 2 SCREW (8-32 x 5/8) LOCKWASHER 29 2 WASHER 30 1 SLEEVE 31 2 PLATE NOVEMBER 1999 Pge 3D-11

12 Fuel Mngement System A = LARGE SCREW (5 MM) (TORQUE TO 30 LB. IN. (3.4 N.M) B = SMALL SCREW (4MM)(TORQUE TO 20 LB. IN. (2.3 N.M) Pge 3D NOVEMBER 1999

13 Fuel Mngement System TORQUE REF. NO. QTY. DESCRIPTION l. in. l. ft. N m 1 FUEL MANAGEMENT ASSEMBLY 1 1 VAPOR SEPARATOR BODY KIT 2 1 O RING 3 1 MOUNTING SCREW KIT 4 1 COLLAR 5 3 GROMMET 6 3 WASHER 7 3 WASHER 8 3 LOCKWASHER 9 3 SCREW DRAIN SCREW KIT 11 1 CHECK VALVE 12 1 FLOAT KIT 13 1 FLOAT VALVE KIT 14 1 SCREW KIT 15 1 COVER KIT 16 1 ELBOW KIT (Sme s Ref. #15 on pge 19) 17 1 ATTACHING KIT PRESSURE REGULATOR KIT 19 1 SCHRADER VALVE KIT TUBING KIT 21 1 FUEL PUMP FITTING KIT 22 1 O RING/SEAL KIT 23 1 FUEL PUMP KIT 24 1 FUEL STRAINER KIT 25 1 ELECTRICAL CONNECTION KIT 26 1 NUT (M4 x.7) LOCKWASHER 28 1 NUT (M5 x.8) DECAL-EPA INFO (1998) NOVEMBER 1999 Pge 3D-13

14 Fuel Pump A Perfect Sel ( ) A = TO VAPOR SEPARATOR Pge 3D NOVEMBER 1999

15 Fuel Pump TORQUE REF. NO. QTY. DESCRIPTION l-in l-ft Nm. 1 FUEL PUMP ASSEMBLY 1 1 FUEL PUMP ASSEMBLY 2 1 CHECK VALVE 3 1 DIAPHRAGM 4 2 RETAINER 5 1 SPRING 6 1 CAP 7 1 SPRING 8 1 CAP 9 1 DIAPHRAGM 10 1 GASKET se 11 1 GASKET-Boost 12 1 GASKET-Pulse 13 1 PLATE fuel pump 14 2 ELBOW 15 2 SCREW pump to crnkcse (M6 x 50) SCREW fuel pump (M5 x 40) BASE fuel pump 18 1 FUEL LINE (6 IN.) 19 2 STA STRAP 20 1 FUEL LINE (10-1/2 IN.) 21 1 CONNECTOR 22 1 TUBING (15-1/2 IN.) 23 1 TUBING (19 IN.) 24 1 FUEL FILTER ASSEMBLY 25 1 PROBE 26 1 FUEL FILTER BASE 27 1 CONNECTOR (STRAIGHT) 28 1 ELBOW 29 2 SCREW (1/4-20 x 1-1/8 IN.) NOVEMBER 1999 Pge 3D-15

16 Electronic Fuel Injection (EFl) System Introduction The trouleshooting informtion provided here consists of preliminry checks (checks to e followed efore proceeding with EFI tests), digrms (fuel flow nd electricl wiring), component description (from digrms), flow chrts (low pressure fuel delivery, high pressure fuel delivery, fuel delivery vs. electricl delivery), prolem dignosis, nd series of test nd check procedures tht will help isolte prolems ssocited with the fuel injection system. Ech test/check (listed) cn e completed without mjor fuel system disssemly. Using the Test Procedures EFI System Tests Sfety Precutions Red the entire test efore eginning to perform outlined procedures. Study the RESULTS mteril prior to testing. This will help in determining tht ech test is providing desired results. EFI Electricl System nd ECM Check Fuel Guge Connection/Pressure Test Vpor Seprtor Fuel Delivery Test Vpor Seprtor Flot Test Wter Seprting Filter Flow Test Pulse Fuel Pump Delivery Test Finl Filter Check Fuel Pressure Regultor Test Electric Fuel Pump Test Injector Electricl Test Injector Fuel Delivery Test Injector Operting Test (Mnifold Cover Removed) Induction Mnifold Lek Check (Mnifold Cover Removed) Sensor Tests CAUTION Alwys use pproved sfety glsses or goggles when working on pressurized fuel systems. DANGER Motor fuels re extremely flmmle. Do not show open sprks or flmes when working ner fuel systems. WARNING To void potentil fire hzrds, use extreme cution when connecting nd disconnecting fuel line connections nd test dptors. Do not llow fuel to spill on hot engine prts or on live electricl connections. Pge 3D NOVEMBER 1999

17 Wipe up fuel spills immeditely. CAUTION CAUTION FUEL INJECTION Depressurize fuel system prior to opening line connections or removing fuel system components. DANGER Perform the tests in this section in well ventilted re to void eing overcome y fuel vpors or poisonous exhust gses. Fuel Injection System Function Preliminry Checks Ignition Sprk Check Fuel is delivered directly to the engine y wy of fuel injectors. These injectors re provided with constnt supply of fuel (34 to 36 psi; 234 to 238 kp) delivered to the fuel ril. The injectors re opened nd closed electroniclly y the Electronic Control Module (ECM). The ECM receives input signls from vrious sensors in the EFI system which in turn trnsmits controlling outputs (open/close) to the injectors. The length of time the injectors sty open is considered pulse width. The pulse width will widen (richer) or nrrow (lener) depending on signls ECM receives from sensors, to llow efficient opertion t ll speeds nd conditions. IMPORTANT: The following preliminry steps MUST BE FOLLOWED efore ttempting EFI prolem dignosis. Purpose: This test determines if the ignition system is delivering usle sprk to the sprk plugs. By performing this test, the prole cuse cn e isolted to either the ignition system or fuel system. 1. Disconnect ll sprk plug wires from sprk plugs. 2. Connect sprk gp tester Quicksilver ( T) to good ground on engine. Connect Sprk Plug Extensions ( A1) etween tester nd sprk plug leds. 3. Connect Remote Strter Switch Quicksilver ( A1).. Connect RED led from switch to lrge positive (+) terminl with RED nded cle ttched [(+) cle from ttery].. Connect BLACK led from switch to smll terminl with YELLOW/RED led ttched. 4. Turn ignition key switch to the ON position. OFF ON START Results: 5. Look t sprk gp tester viewing port for presence of good qulity sprk. IMPORTANT: The presence of good sprk will not necessrily indicte condition of timing. Ignition timing my e off fr enough to prevent the engine from strting, ut still llow good sprk to e present in the sprk gp tester NOVEMBER 1999 Pge 3D-17

18 A stedy, lue sprk should e present t ech sprk plug wire. If good sprk is present, prolem my not e ignition relted. If good sprk is not present, prolem my e ignition relted. Troule shoot ignition system or mke sure engine timing is set correctly. Refer to pproprite ignition section in this service mnul. Ignition system filure (switch ox, sttor, trigger, etc.) cn cuse fuel delivery prolems. Injectors re triggered in pirs y one, three, five primry circuits (inner switch ox). No. 1 Primry Triggers No. 3 & 4 Injectors No. 3 Primry Triggers No. 5 & 6 Injectors No. 5 Primry Triggers No. 1 & 2 Injectors Filure in one or more of these primry circuits will cuse no sprk nd no fuel to respective cylinders (ove). Check sprk nd sprk plugs on ll cylinders efore ttempting EFI tests. Electronic Fuel Injection Set Up Fresh Qulity Fuel IMPORTANT: Follow EFI Timing/Synchronizing/Adjustment section 2C efore ttempting tests on EFI system. EFI set up procedures must e followed efore tests on system re performed (refer to Section 2C). Improper set up cn result in poor engine performnce (i.e. uncontrollle idle speeds, len sneezing, low power during ccelertion or engine will simply not run.) Filure to properly set up the EFI system cn led to misdirections in solving simple prolems in the EFI system. Low Bttery Voltge Using remote fuel tnk contining mjor rnd of premium unleded gsoline, test run the sport jet to eliminte ny prolems relted to restricted fuel supply (clogged lines, mlfunctioning nti-siphon vlve, etc.) nd/or mrginl gsoline. Low ttery voltge cn cuse EFI system to deliver fuel in n inconsistent mnner. Inspect ttery connections nd chrging system, refer to Section 2B. The EFI system requires sustntil mount of voltge to function properly. Operting engine t low RPM for n extended period of time cn cuse low voltge. Pge 3D NOVEMBER 1999

19 Fuel Flow Digrm FUEL INJECTION f d e g c h v r p q o i u s n k j m -Fuel Injectors (6) -Fuel Ril c -Fuel Ril Pressure Port d-fuel Pressure Regultor Mnifold Hose e -Fuel Pressure Regultor f -To Strord Bleed Junction Block g-to Port Bleed Junction Block h-needle nd Set i -Wter Seprtor j -Wter Sensor k -Pulse Fuel Pump l -From Fuel Tnk vi Electric Pump t l m-electric Fuel Pump n-from Oil Pump o-vpor Seprtor p-vpor Seprtor to Mnifold Vent Hose q-vpor Seprtor Flot r -Electric Fuel Pump s -Mnifold t -Injector Wiring Hrness u-finl Filter v -Armture NOVEMBER 1999 Pge 3D-19

20 Fuel Flow Component Description Electric Fuel Pump (m) Pulse Fuel Pump (k) Wter Seprting Filter (i) Vpor Seprtor (o) Bleed System (f,g) Finl Filter (u) Activted y solenoid when ignition key is turned to the RUN position. Pump wiring is protected y 20 mpere fuse. Pump drws fuel from ot fuel tnk nd delivers fuel to pulse fuel pump. Pump output is 2 5 psi ( vdc. The pulse fuel pump opertes through lternting crnkcse pressure to deliver fuel through the wter seprting filter to the vpor seprtor. Fuel Idle 2 3 psi ( kp) [Minimum 1 psi (6.9 kp)]. Fuel Wide-Open-Throttle 6 8 psi ( ) [Minimum 4 psi (27.6 kp)]. The wter seprting filter protects the fuel injectors from wter nd deris. The filter contins sensor proe which monitors wter level in the filter. If wter is ove the sensor proe, the wter detection light will come on nd the wrning horn will egin series of eeps. The vpor seprtor is fuel reservoir which continuously lends nd circultes fresh fuel, oil nd unused fuel/oil from the fuel ril.. Fuel Inlet Fresh fuel delivered from the wter seprtor y the crnkcse mounted pulse fuel pump. The mount of fuel llowed to enter the vpor seprtor is controlled y needle/set nd flot ssemly mounted in the cover of the vpor seprtor.. Oil Inlet Oil delivered y the crnkshft driven oil pump. c. Crnkcse Bleed Inlet Recirculted (unurned) fuel/oil mixture delivered from the leed lines through filter into the vpor seprtor. d. Fuel Pressure Regultor Inlet Unused fuel/oil mixture eing recirculted from the fuel ril ck into the vpor seprtor. On crureted engines, excess fuel which collects in the crnkcse is chnneled into the trnsfer ports to e urned. On EFI engines, excess crnkcse fuel is emptied into the vpor seprtor. It mixes with fresh incoming fuel nd is pumped to the fuel ril nd fed through the injectors. The finl filter is locted elow the electric fuel pump in the vpor seprtor. The filter collects deris nd prevents them from flowing through the electric pump nd into the fuel ril nd injectors. Electric Fuel Pump (Inside Vpor Seprtor) (r) The electric fuel pump runs continuously while providing fuel in excess of engine demnds. The excess fuel is circulted through the fuel ril to the fuel pressure regultor nd ck to the vpor seprtor. Norml fuel pressure is psi (234 to 248 kp). Pge 3D NOVEMBER 1999

21 Fuel Injectors () Induction Mnifold (s) FUEL INJECTION The fuel injectors re locted inside the induction mnifold on the fuel ril. The injector vlve ody consists of solenoid ctuted needle nd set ssemly. The injector receives signls from the EFI Electronic Control Module. These signls determine how long the needle is lifted from the set (pulse width) llowing mesured fuel flow. The pulse width will widen (richer) or nrrow (lener) depending on vrious signls received from sensors connected to the EFI ECM. The ECM receives signls from the primry ignition circuit of cylinders #1, #3 nd #5 to fire ech pir of injectors ccordingly. A four wire hrness connects the fuel injectors to the ECM. The RED wire is t 12 volts nd connects to ll injectors. The BLUE, YELLOW nd WHITE wires ech go to pir of injectors nd re normlly t 12 volts for zero differentil. To fire the injectors this voltge is rought down to ner ground creting potentil cross the injectors. The induction mnifold is common plenum chmer for ccurte pressure mesurement. It contins 4 throttle shutters on 2 throttle shfts. The shutter opening (idle ir opening) cn e djusted during EFI set-up procedure. The mnifold contins the fuel ril, injectors, throttle position sensor nd ir temperture sensor. A fuel ril pressure port is locted on the fuel pressure regultor. Fuel Pressure Regultor (e) The fuel pressure regultor is locted on top of the vpor seprtor nd is continuously regulting fuel pressure produced y the electric fuel pump. The electric pump is cple of producing 90 psi (621 kp) of fuel pressure. The pressure regultor limits fuel pressure t the injectors to 34 to 36 psi (234 to 248 kp). EFI Electricl Components ELECTRONIC CONTROL MODULE (ECM) The ECM is continully monitoring vrious engine conditions (engine temperture, engine detontion control, engine throttle opening) nd climte conditions (induction ir temperture, rometric pressure nd ltitude level) needed to clculte fuel delivery (pulse width length) of injectors. The pulse width is constntly djusted (rich/len conditions) to compenste for operting conditions, such s crnking, cold strting, climte conditions, ltitude, ccelertion nd decelertion, llowing the outord to operte efficiently t ll engine speeds. 12 Volt Bttery - The 12 volt ttery provides power to the ECM even with the ignition switch in the OFF position. IMPORTANT: When disssemling EFI System DISCONNECT BATTERY CABLES. Strter Solenoid - Provides 12 volt signl when key is in the strt position. In the strt position, injector pulse widths re tripled when engine hed temperture is elow 90 F (32.2 C) to provide dequte fuel for quick strt up. When key is returned to the run position or engine hed temperture is ove 90 F (32.2 C), pulse widths return to norml vlue. Fuel Injectors - A four wire hrness connects the fuel injectors to the ECM. The red wire is t 12 volts nd connects to ll injectors. The lue, yellow nd white wires ech go to pir of injectors nd re normlly t 12 volts for zero differentil. To fire the injectors this voltge is rought down to ner ground creting potentil cross the injectors NOVEMBER 1999 Pge 3D-21

22 Electric Fuel Pump - The ECM contins fuel pump driver circuit tht provides power to the electric fuel pump. The fuel pump does not hve its negtive terminl (-) BLACK/RED wire grounded to the pump housing. The fuel pump positive terminl (+) RED wire nd the negtive terminl (-) re t 12 volts with the ignition switch in the off position for zero differentil. When the pump is on, the negtive terminl is rought down to ner ground (i.e. 1.5 volts). SENSOR INTERACTION WITH THE ECM IMPORTANT: DO NOT run engine for extended periods of time with sensors disconnected or ypssed (shorted). Serious engine dmge my result. AIR TEMPERATURE SENSOR The ir temperture sensor trnsmits mnifold solute ir temperture, through full RPM rnge, to the ECM. As ir temperture increses sensor resistnce decreses cusing the ECM to decrese fuel flow (lener mixture). Disconnecting the ir temp sensor (open circuit) will increse fuel flow (richen mixture) y 10%. Bypssing ir temp sensor (short in circuit) will cuse fuel flow to decrese 10%.The ir temperture sensor circuit cn e tested using the EFI tester. The ir temperture sensor cn e tested following ir temperture sensor test on pge 3D-44. MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR The mp sensor is non-servicele sensor mounted in the ECM ox. The MAP sensor is used to sense chnges in mnifold solute pressure nd is connected to the intke mnifold y the wy of vcuum hose. The MAP sensor is functioning through the full RPM rnge nd is continully signling induction mnifold pressure redings to the ECM. The ECM in turn determines fuel flow s signls re received. Drwing vcuum on the MAP sensor hose will crete len fuel condition ltering engine opertion. If no chnge occurs when drwing vcuum, MAP sensor is not functioning properly. MAP sensor cn e tested with the DDT tester. ENGINE HEAD TEMPERATURE SENSOR The Engine Hed Temperture Sensor provides the ECM signls relted to engine temperture to determine level of fuel enrichment during engine wrm up. The ECM is receiving informtion t ll engine tempertures ut stops fuel enrichment t n engine temperture of 90 F (32 C). An open circuit on the temperture sensor will increse fuel flow up to 40% ut will not e ffected t wide open throttle. If no chnge occurs when sensor is disconnected, sensor my not e functioning properly. The engine hed temperture sensor cn e tested following Engine Hed Temperture Sensor Test on pge 3D-46. NOTE: If sensor does not mke clen contct with cylinder hed rich condition my exist. THROTTLE POSITION SENSOR (TPS) The TPS trnsmits informtion to the ECM during low speed nd mid rnge opertion, relted to throttle ngle under vrious lod conditions. TPS djustment is criticl step in engine set up (Section 2C). Disconnecting the TPS will increse fuel flow 40% t idle ut does not effect WOT. The TPS cn e tested following the Throttle Position Sensor Test on pge 3D-47. NOTE: The higher the voltge, the richer the fuel flow. Refer to TPS Adjustment (Section 2C). Pge 3D NOVEMBER 1999

23 WATER SENSING SYSTEM The system consists of wter seprting fuel filter (strord side powerhed), sensing proe (ottom of filter) nd wter sensing module (elow ECM ox). The wter sensing module hs four wires: PURPLE - Connects to 12 volt power supply. LIGHT BLUE - Connects to lue lert, which sounds the wrning horn when ctivted. TAN - Connects to sensing proe. BLACK - Connects to ground. WATER SENSING SYSTEM FUNCTION 1. The filter seprtes the ccumulted wter from the fuel. 2. A voltge is lwys present t sensing proe. When wter reches top of proe it completes the circuit to ground. 3. The completed circuit ctivtes the wrning. The wrning hs 5-10 second dely, then the module s red light illumintes nd wrning horn intermittently sounds. The system cn e tested y disconnecting the TAN wire from sensor proe nd holding to good engine ground connection for 10 seconds NOVEMBER 1999 Pge 3D-23

24 EFI Fuel Mngement (Low Pressure Fuel Route) Perform ll preliminry checks 3D-13. Instll fuel pressure guge on to mnifold pressure port. Plce ignition switch in OFF position 30 seconds efore testing. Plce ignition switch in ON position nd note pressure within 30 seconds (34 to 36 psi; 234 to 248 kp). Pump does not run No or low fuel pressure Fuel pressure ove 36 psi (248 kp) Follow High Pressure Fuel Route Flow Chrt. Perform Vpor Seprtor Fuel Delivery Test. Follow High Pressure Fuel Route Flow Chrt. Results Results No or little fuel flow from vpor seprtor. Reconnect hose. Fuel flows freely from vpor seprtor. Reconnect hose. Check in-line Filter Perform Vpor Seprtor Flot Test. Follow High Pressure Fuel Route Flow Chrt. Results Results Fuel flows from fresh fuel inlet hose. Little or no flow from fresh fuel inlet hose. Reconnect hose. Inspect flot system of vpor seprtor. Perform Wter Seprting Filter Flow Test. Results Results Low or no fuel flow from wter seprting inlet hose. Reconnect hose. Fuel flows freely from wter seprting filter inlet hose. Reconnect hose. Perform Pulse Fuel Pump Delivery Test. Replce wter seprting filter. Results Results Fuel flows freely from pulse pump inlet hose. No fuel flow to pulse fuel pump. See pulse pump removl nd inspection section 3A. Locte ll frgments of filed pump efore ressemly. Check for restrictions, holes or loose connections from fuel supply. Pge 3D NOVEMBER 1999

25 EFI Fuel Mngement (High Pressure Fuel Route) FUEL INJECTION Perform low pressure checks efore performing checks on high pressure route. Instll fuel pressure guge (P/N A2) on to mnifold pressure port. Plce ignition switch in OFF position 30 seconds efore testing. Plce ignition switch in ON position nd note pressure within 30 seconds (34 to 36 psi; 234 to 248 kp). Fuel pressure ove 36 psi (248 kp) No or low fuel pressure Pump does not run Clogged or fulty fuel pressure regultor remove nd replce. Perform Finl Filter Check Perform Electric Fuel Pump Voltge Test. Results Results Finl filter OK. Finl filter clogged. Perform Fuel Pressure Regultor Test. Clen or replce finl filter. Results Stedy strem of fuel (pressure still elow 34 psi). Results Low or no fuel flow. Replce fuel regultor. Perform Electric Fuel Pump Voltge Test. Results Results Voltge from ECM driver circuit OK. Low or inconsistent voltge from ECM driver circuit. Replce fuel pump. Replce ECM NOVEMBER 1999 Pge 3D-25

26 Fuel Ril Electricl/Fuel Determintion Perform ll preliminry checks pge 3D-17. Adequte fuel pressure (34 to 36 psi; 234 to 248 kp) follow Low/High Fuel Route Flow Chrts. Plce sport jet in wter nd run engine etween 2000 nd 2500 RPM. With engine running ( RPM) remove sprk plug leds one t time using insulted pliers. Results Results No RPM chnge on cylinder(s), indicting prolem in cylinder(s). RPM decreses (on ech cylinder). Perform Injector Electricl Hrness Test. Fuel delivery OK. Results Results Broken circuit to injector. Injector circuit tests OK. Perform Induction Mnifold Disssemly nd inspection. Perform Injector Fuel Delivery Test. Results Results RPM increse occurs. No RPM chnge. Perform induction mnifold disssemly. Inspect injector nd filter. Results Perform compression check on prolem cylinder. Results Low or no compression on cylinder. Compression OK. Inspect cylinder ore. Refer to Section 4 for disssemly. NOTE: Injector filters must e inspected prior to ressemly. Check: 1) Dmged reeds 2) End cp sels 3) Crnkcse split line lek 4) Crnkshft seling rings Pge 3D NOVEMBER 1999

27 EFI System Test Procedures FUEL INJECTION Fuel Guge Connection/Pressure Test IMPORTANT: When checking fuel pressure while engine is running, fuel pressure my fluctute. Fuel pressure fluctution (i.e. 34 to 36 psi 234 to 248 kp ) is common, s the regulted pressure is differentil etween fuel ril nd mnifold vcuum. Purpose: Checking fuel mnifold pressure ensures tht fuel under usle pressure is ville to the fuel injectors. This test isoltes the prole cuse s either fuel delivery or EFI electricl system filure. IMPORTANT: Fuel pressure should e monitored through full RPM rnge to determine fuel supply prolems t high engine speeds. 1. Connect fuel pressure guge to induction mnifold pressure port Pressure Port 2. Turn ignition key switch to On position OFF ON START 3. Operte electric fuel pump for pproximtely 10 seconds. NOTE: Fuel pump will only operte for pproximtely 30 seconds. By turning the key switch to OFF nd then ck to ON the pump will operte for 30 seconds more. 4. Tke reding on fuel pressure guge. Results: If pressure reding is 34 to 36 psi (234 to 248 kp), the electric fuel pump is providing fuel with enough pressure to e used y the injectors. Pump mlfunction is not the cuse of EFI troule. If fuel pressure is well elow 34 psi (234 kp), fuel delivery to electric fuel pump, fuel pump filure or other relted prolem exists. Follow low/high fuel pressure flow chrts. If fuel pressure is ove 36 psi (248 kp) go to fuel pressure regultor test NOVEMBER 1999 Pge 3D-27

28 Vpor Seprtor Fuel Delivery Test Purpose: Verifying there is dequte fuel flow to the electric fuel pump (through full RPM rnge) will determine components in low pressure fuel system re functioning correctly. 1. Remove vpor seprtor drin plug nd plce clen continer under drin. Results: If fuel flow is present, fuel is eing delivered to electric fuel pump. Go to high pressure flow chrt. If fuel flow is not present, proceed to step Plce emergency stop switch in OFF position to prevent engine from strting. If ot is not equipped with emergency stop switch, connect jumper led from the BLACK/ YELLOW terminl on the switch ox to engine ground. 3. Turn ignition key switch to START nd operte strter motor for 10 to 20 seconds Look for fuel flow from hose. Results: If low or no fuel flow is present, inspect wter seprting fuel filter nd perform Vpor Seprtor Flot Test Pge 3D NOVEMBER 1999

29 Vpor Seprtor Flot Test Purpose: This test will indicte if flot is stuck in the up position. FUEL INJECTION NOTE: If flot is stuck down, vpor seprtor will over flow cusing rich condition. 1. Remove fuel inlet hose from vpor seprtor nd put end of hose in clen continer. 2. Remove ll sprk plugs from engine to prevent engine from strting. 3. Turn ignition key switch to START position nd operte strter motor for 15 to 20 seconds. OFF ON START 4. Look for fuel flow from hose. Results: If fuel flow is present t hose, remove, disssemle nd inspect flot ssemly. See vpor seprtor disssemly. If fuel flow is low or not present, perform Wter Seprting Filter Flow Test NOVEMBER 1999 Pge 3D-29

30 Wter Seprting Filter Flow Test Purpose: This test will indicte if wter seprting filter is clogged. 1. Remove fuel inlet hose to wter seprting filter. Put end of hose in clen continer. 2. Plce emergency stop switch in OFF position to prevent engine from strting. If ot is not equipped with emergency stop switch, connect jumper led from the BLACK/ YELLOW terminl on the switch ox to engine ground. 3. Turn ignition key switch to START nd operte strter motor for 10 to 20 seconds. OFF ON START 4. Look for fuel flow from hose. Results: Fuel flows from wter seprting inlet hose. Remove nd replce clogged filter Low or no fuel flow from wter seprting inlet hose. Perform electric fuel pump delivery test. If test results re ok, disssemle pulse fuel pump nd inspect for dmged check vlves, gskets, etc. All frgments of filed pump must e locted efore ressemly. Pge 3D NOVEMBER 1999

31 Electric Fuel Pump Delivery Test FUEL INJECTION Purpose: This test will indicte if the electric fuel pump is cple of supplying dequte fuel to the pulse pump. 1. Remove inlet hose to pulse fuel pump nd put end into clen continer Plce emergency stop switch in OFF position to prevent engine from strting. If ot is not equipped with emergency stop switch, connect jumper led from the BLACK/ YELLOW terminl on the switch ox to engine ground. 3. Turn ignition key switch to START position nd operte strter motor for 15 to 20 seconds. OFF ON START 4. Look for fuel flow from hose. Results: If fuel does not flow from electric pump outlet hose, inspect 20 mpere fuse. If fuse is ok, check for ttery voltge t electric fuel pump. If ttery voltge is not present or is low, replce pump solenoid. If correct voltge is present, replce electric fuel pump NOTE: If voltge to pump is correct nd pump is running ut little or no fuel is exiting fuel hose, inspect for loose fuel hose connections (pump is drwing ir), pinched fuel hose, stuck nti-siphon vlve or clogged fuel filter in ot fuel tnk NOVEMBER 1999 Pge 3D-31

32 Finl Filter Check nd De-pressurizing EFI System Procedures Purpose: Checking the finl filter for ostructions, dmge etc. elimintes this component s possile source of restriction in the system. 1. De-pressurize EFI fuel system y wrpping clen cloth round pressure port vlve nd inserting tip of screwdriver into vlve, depressing vlve core. Let fuel drin from vlve Pressure Port 2. Remove drin plug from vpor seprtor nd llow fuel to drin into suitle continer Pge 3D NOVEMBER 1999

33 3. Remove 3 olts securing vpor seprtor ssemly to mnifold. FUEL INJECTION Bolts 4. Tilt vpor seprtor ssemly out from mnifold nd remove 9 screws securing cover. 5. Remove vpor seprtor tnk from cover. 6. Rotte inlet filter counterclockwise nd pull downwrd to remove filter from fuel pump. -Inlet Filter 7. Inspect filter for deris or dmge. Results: If filter is clogged with deris, clen filter with solvent nd compressed ir or replce filter. Ressemle vpor seprtor to mnifold nd recheck fuel pressure. If pressure is still elow 34 psi (234 kp), perform fuel Pressure Regultor Test NOVEMBER 1999 Pge 3D-33

34 Pressure Regultor Test Purpose: This test will determine if wek, plugged or open pressure regultor is cusing indequte fuel pressure in the system. 1. Connect pressure guge to EFI test port A Test Port 2. Turn ignition key switch to ON position nd check fuel pressure reding on guge. If pressure reding is elow 34 psi (234 kp) go to step 3 following. OFF ON START 3. Remove fuel pressure regultor, ut do not disconnect ny hoses from regultor. 4. Put dischrge end of regultor in clen continer. 5. Turn ignition key switch to ON position. OFF ON START Pge 3D NOVEMBER 1999

35 6. Check for fuel flow out of regultor. FUEL INJECTION Results: If stedy strem of fuel exits regultor into continer nd pressure is elow 34 psi (234 kp), replce pressure regultor. If low or no fuel exits regultor into continer nd pressure is elow 34 psi (234 kp), perform voltge checks on electric fuel pump, following. If low or no fuel flow exits regultor into continer nd pressure is ove 36 psi (248 kp), replce regultor NOVEMBER 1999 Pge 3D-35

36 Electric Fuel Pump Voltge Test CAUTION When checking voltge t pump, DO NOT pry oot covers off terminls with metl oject, s ech terminl is t 12 volts when engine is off. Serious dmge to electric fuel pump nd/or ECM ox cn result. Purpose: If insufficient electricl power is ville t the pump, no or low fuel pressure will e developed. 1. Set volt meter to red ttery voltge nd connect lck test led to ground, positive test led to positive (+) post of fuel pump. NOTE: Positive test led cn e pierced through oot cover for testing. Refer to voltge test chrt (pge 3D-37) for voltge redings. Positive Test Terminl -Positive (+) Terminl Pge 3D NOVEMBER 1999

37 2. Set volt meter to red ttery voltge nd connect BLACK test led to ground, POS- ITIVE test led to NEGATIVE ( ) post of fuel pump. Negtive Test Terminl -Negtive ( ) Terminl 3. Perform voltge tests elow. VOLTAGE TEST CHART Engine Mode BLACK Meter Led to Engine Ground; RED Meter Led to: Approximte Voltge Reding If Approximte Voltge is not otined, this indictes: 1. All models (+) terminl of fuel pump volts If reding is elow 12 volts, the ttery is d, dischrged or hs d connection(s). If reding is higher thn 13.5 volts, the ttery is overchrged 2. Ignition key in OFF position. 3. Ignition key in ON position nd engine NOT running. 4. Engine eing crnked. ( ) terminl of fuel pump. ( ) terminl of fuel pump. ( ) terminl of fuel pump. Sme reding should e otined s reding in check No. 1 (ove) 1.5 volt or less (voltge should rise to volts fter pproximtely 30 seconds. If reding is lower thn in test 1, the ECM is d or there is n open circuit in fuel pump. Bd ECM or d fuel pump*. 1.5 volt or less. Bd ECM or d fuel pump.* *Check for proper electricl opertion of electric fuel pump. (Step 4) NOVEMBER 1999 Pge 3D-37

38 4. Disconnect BLACK/RED wire to negtive terminl on electric fuel pump. Connect ground jumper wire from negtive pump terminl to good engine ground. Results: Pump does not operte. Replce electric fuel pump. Pump opertes. But, pressure reding does not chnge when performing electric fuel pump pressure test. Replce electric fuel pump. Pump opertes. Check BLACK/RED ( ) led nd hrness for good continuity. NOTE: BLACK/RED led is connected to pin 2 of EFI hrness Pge 3D NOVEMBER 1999

39 Injector Electricl Hrness Test FUEL INJECTION Purpose: This test will determine if electricl or fuel delivery prolem exists during the fuel delivery process y checking for open circuits in injector hrness. 1. With outord in wter, strt nd llow to wrm up. Rise engine speed to RPM. Remove sprk plug leds one t time nd note RPM chnge. Determine non-working (no RPM chnge) cylinder. Stop engine. 2. Disconnect injector hrness (4 pin connector). IMPORTANT: Use DMT Tester ( A1) nd Test Hrness ( A1) when testing injector hrness. 3. Connect digitl ohmmeter (dil set t 200 scle) leds. POSITIVE led from ohmmeter connects to POSITIVE prong 2 (RED wire) of hrness connector. Connect NEG- ATIVE led from ohmmeter to the remining wires of hrness connector s follows: WHITE Led = Injectors, Cylinders 1 nd 2 DARK BLUE Led = Injectors, Cylinders 3 nd 4 YELLOW = Injectors, Cylinders 5 nd 6 1 -YELLOW 2 -RED 3 -DARK BLUE 4 -WHITE Results: If redings re 1.1 ±.2 oth injector circuits re complete. Perform Injector Fuel Delivery Test If redings re 2.2 ±.2 one injector does not hve complete circuit. Perform induction mnifold disssemly nd inspection following NOVEMBER 1999 Pge 3D-39

40 ECM Injector Driver Test To verify tht the ECM is operting the injector pirs, connect test hrness etween mnifold connector nd engine hrness. Strt engine. Use DVA meter ( ) or DMT ( T1). Set meter to 200 scle. Connect BLACK meter led to engine ground nd RED test led to ech BLUE, WHITE or YELLOW femle ullet connector Norml voltge for 2.5L engine will e 25 to 60 volts. Voltge will vry with RPM. Injector Fuel Delivery Test Purpose: This test will determine if injector is delivering fuel when signl is received. NOTE: It is recommended tht the Digitl Dignostic Terminl A2 e utilized following the procedure listed with its instruction mnul. Injector Opertion Test (Mnifold Cover Removed) Purpose: This test determines if the injectors re ctully injecting fuel into the engine t norml rte. WARNING Do not strt engine with induction mnifold cover removed. Disle ignition system prior to doing this test. 1. Remove induction mnifold cover using procedures outlined under lnduction Mnifold Removl. Pge 3D NOVEMBER 1999

41 2. Re-ttch induction mnifold to engine using 1/4-20 x 2-3/4 screws. FUEL INJECTION 3. Connect jumper wire etween the ECU metl cse nd good engine ground. 4. Disconnect ll sprk plug wires from sprk plugs nd sel leds with electricl tpe to prevent sprking. 5. Put ignition key switch in START position. OFF ON START 6. Look t injector spry pttern using n explosive proof flshlight. Results A: If fuel spry is not present in ll injectors or spry pttern is extremely wek, check wiring hrness to injector connectors, or injector filters for plugging. If spry ptterns re ville in most of the injectors, ut not ll, perform Procedure B. 7. Connect EFI tester. Steps outlined in electricl system nd ECM check. 8. Connect remote strter Quicksilver ( A1) to NEGATIVE terminl of electric fuel pump nd good engine ground. Depress remote strt switch, pump will operte s long s switch is depressed. WARNING Do not operte pump for more thn 20 seconds continuously NOVEMBER 1999 Pge 3D-41

42 9. Perform fuel injector test procedures (outlined) while depressing remote strter switch. Results B: If fuel spry is present using EFI tester, ut not present while crnking, perform switch ox DVA tests Section 2A (1, 3, 5 switch ox filure). If fuel spry pttern is equl on ll injectors, system is functioning normlly Pge 3D NOVEMBER 1999

43 Induction Mnifold Lek Check (Mnifold Cover Removed) FUEL INJECTION Purpose: Lck of good fuel pressure my e cused y n internl lek in the fuel induction mnifold nd not cused y wek pump. This test elimintes the possiility of induction mnifold leks s prole cuse. WARNING Do not strt engine with induction mnifold cover removed. Disle ignition system prior to performing this test. WARNING Opertion of EFI system with cover removed cn llow fuel to spry components. Be extremely creful when operting the fuel system in this condition. 1. Remove induction mnifold cover using procedures outlined under Induction Mnifold Removl. 2. Rettch mnifold ody without cover to engine using twelve 1/4-20 x 2-3/4 screws in plce of screws normlly used. 3. Connect jumper wire etween the metl cse of ECM nd good engine ground. WARNING If serious lek is present in the induction mnifold, fuel my spry out of d sel. Hve clen up rgs ville to remove excess fuel from components NOVEMBER 1999 Pge 3D-43

44 4. Plce emergency stop switch in OFF position to prevent engine from strting. If ot is not equipped with emergency stop switch, connect jumper led from the BLACK/ YELLOW terminl on the switch ox to engine ground. 5. Connect remote strter Quicksilver ( A1) to NEGATIVE terminl of electric fuel pump nd good engine ground. Depress remote strt switch, pump will operte s long s switch is depressed. WARNING Do not operte pump for more thn 20 seconds continuously Look for lek points on induction mnifold while depressing remote strter switch. Results: If no leks re present, replce cover nd gsket using norml length screws. If fuel lek is present etween seling surfces, reuild system using new o-rings. Pge 3D NOVEMBER 1999

45 Air Temperture Sensor Test FUEL INJECTION Purpose: This test elimintes possiilities of improper fuel delivery relted to ir temperture sensor. 1. Disconnect nd remove Air Temperture Sensor from induction mnifold. 2. Connect DMT ( T1) to leds of sensor. 3. Plce sensor in ice wter while monitoring meter reding. Use grph (elow) for reference. NOTE: Temperture/resistnce reding my differ slightly from grph curve. AIR TEMP. SENSOR RESISTANCE (K OHMS) SENSOR RESISTANCE VS. AIR TEMPERATURE Results: Resistnce does not chnge inversely with temperture chnge. Replce defective Air Temperture Sensor. Resistnce chnges inversely with temperture chnge. Air Temperture Sensor OK NOVEMBER 1999 Pge 3D-45

46 Engine Hed Temperture Sensor Test Purpose: This test elimintes possiilities of improper fuel delivery relted to the wter temperture sensor. 1. Disconnect nd remove Engine Hed Temperture Sensor (see pge 3D-51). 2. Connect DMT ( T1) to ullet leds of sensor. 3. Plce sensor in ice wter while monitoring meter reding. Use grph (elow) for reference. NOTE: Temperture/resistnce reding my differ slightly from grph curve. Results: Resistnce does not chnge inversely with temperture chnge. Replce defective Engine Hed Temperture Sensor. Resistnce chnges inversely with temperture chnge. Engine Hed Temperture Sensor OK. Pge 3D NOVEMBER 1999

47 Throttle Position Sensor Test FUEL INJECTION Purpose: This test elimintes possiilities of improper fuel delivery relted to the throttle position indictor. Refer to EFI electricl system nd ECM test. NOTE: Engine hrness MUST BE disconnected from the EFI tester A2 (if eing used) nd reconnected in the norml running configurtion in order to test or djust the throttle position sensor. IMPORTANT: TPS cn e djusted using digitl meter (DMT). Anlog (needle) type my e used lthough it my e difficult to red the low voltge setting ccurtely with most meters. 1. Disconnect TPS from EFI hrness Throttle Position Sensor (TPS) -TPS Hrness Connector 2. Connect digitl using TPS Test Led Assemly ( ) etween TPS connector nd EFI hrness connector. Set voltmeter to 2 DC volts. c -TPS Test Led Assemly ( ) TPS Connector c -EFI Hrness Connector IMPORTANT: TAN/BLK hed temperture leds must e disconnected from port cylinder hed efore djusting TPS NOVEMBER 1999 Pge 3D-47

48 3. Disconnect TAN/BLACK engine hed temperture sensor leds locted on port cylinder hed. 4. Turn key to the ON position. 5. Loosen screws securing TPS to mnifold. Mp Sensor Test Screws 6. Rotte TPS fully clockwise (holding throttle shft in closed position). Voltmeter should red If redout is not within specifictions, djust TPS to otin redout of Tighten TPS screws to 20 l. in. (2 Nm) holding correct tolernce. 8. Disconnect remote control cle from throttle lever. 9. Slowly move throttle lever to full open position while monitoring voltge reding. Voltge reding should increse nd decrese smoothly 10. Set volt meter to 20 DC volts. Mximum voltge reding t full throttle is pproximtely 7.46 volts. 11. Remove test led nd reconnect TPS hrness to EFI hrness. 12. Reconnect TAN/BLACK engine hed temperture sensor leds locted on port cylinder hed. NOTE: If engine ppers to run too rich or too len, TPS cn e redjusted. Decresing voltge yields lener mixture. Incresing voltge yields richer mixture. Purpose: This test elimintes possiilities of improper fuel delivery cused y the mp sensor. Refer to Electronic Fuel Injection Tester ( A2) nd its test mnul. The Digitl Dignostic Terminl ( A2) my lso e used to test the MAP Sensor. It will disply n LED filure light, PASS/ NO opertionl indiction s well s numeric disply vlue. Pge 3D NOVEMBER 1999

49 Prolem Dignosis FUEL INJECTION Condition Possile Source Action Engine Down On Power Or RPM Filed Switch Box Refer to Section 2 Electricl nd Ignition Tests. Poor Accelertion Idles Ok, Top Speed Ok Filed Sttor Filed CDM Low Compression Broken Reed Fuel Delivery Prolem Mnifold Fuel Lek Vpor Seprtor Flooding Over, Engine Running Rich. Cylinder Hed Temperture Sensor Circuit Filed. Improper EFI Set Up. Wter Covering Idle Relief Exhust Ports. T.P.S. Filure. MAP Sensor Filure R.F.I. Prolem* Refer to Section 2 Electricl nd Ignition Tests. Refer to Section 2 Electricl nd Ignition Tests. Refer to Section 4 Power Hed. Perform Injector Fuel Delivery Test. Follow Low/High Pressure Fuel Route Flow Chrts nd Fuel Ril Electricl/Fuel Determintion Flow Chrt. Perform Induction Mnifold Lek Check. Check for fuel coming out of vpor seprtor vent hose. Check cylinder hed temperture sensor. Refer to Section 2 Electricl nd Ignition for proper EFI set up procedures. Bots with extended trnsoms or low engine mount cn cuse engine to lod up on ccelertion. Refer to pge 3D-47. Refer to pge 3D-48. Instll BUZ8H Sprk Plugs NOVEMBER 1999 Pge 3D-49

50 Condition Possile Source Action Poor Accelertion Idles Ok, Timing Not Advncing. Check for stuck trigger. Top Speed Ok (Continued) Engine Surges Between 4000 And 5000 RPM Intermittnt Switch Box Filure. Refer to Section 2 Electricl nd Ignition for tests. Engine Idles Ok But Stumles At Off Idle Speeds Engine Idles Rough (My Len Sneeze) Accelertion Ok; Full Throttle Ok Finl Filter Clogging. T.P.S. Improper Adjustment. Injector Connector Prolem. Vpor Seprtor Flooding Over. Injector Filter Clogged. Improper EFI Setup. Filed Switch Box. Filed Or Disconnected EFI Sensors. Fuel Delivery Prolem. Mnifold Fuel Lek. R.F.I.* Prolem. Sttor (High Speed Winding). Induction Mnifold Air Lek. Improper EFI Setup. MAP Sensor Filure. Perform Finl Filter Check. Refer to Section 2 Electricl nd Ignition for T.P.S. djustment. Perform Injector Fuel Delivery Test. Check for fuel coming out of vpor seprtor vent hose. Refer to Injector Fuel Delivery Test. Refer to Section 2 Electricl nd Ignition for proper EFI set up procedures. Refer to Section 2 Electricl nd Ignition Tests. Perform EFI sensor tests. Follow Low/High Pressure Fuel Route Flow Chrts nd Fuel Ril Electricl/Fuel Determintion Flow Chrt. Perform Induction Mnifold Lek Check. Instll BUZ8H Sprk Plugs. Refer to Section 2 Electricl nd Ignition for tests. Check mnifold cover gsket, mnifold to reed lock housing gsket nd reed lock housing to crnkcse gsket. Refer to Section 2 Electricl nd Ignition for proper EFI set up procedures. Refer to pge 3D-48. Pge 3D NOVEMBER 1999