Fuel Supply - Evolution Mitsubishi Lancer Evolution VIII

Scheme 43

1. The fuel tank is located under the floor of the rear seats to provide increased protection and more luggage space.
2. A fuel tank rollover valve assembly is used to prevent fuel from leaking out in case of a collision.
3. A fuel pump module, including fuel pump, fuel filter, reservoir cup and fuel level sensor (main), is utilized to reduce weight and improve serviceability.

INTRODUCTION TO FUEL SUPPLY DIAGNOSIS

The fuel system supplies an appropriate mixture to the engine. The system consists of the fuel tank, fuel filter, fuel pump and fuel pipe that each part. An evaporative emission control system is provided to prevent evaporated fuel from escaping into the atmosphere.

Engine malfunctions caused by insufficient fuel supply and evaporative emission control system operation malfunctions can be caused by faults in the vapor line, fuel pipe, hose, or fuel tank pressure control valve, etc.

FUEL SUPPLY DIAGNOSTIC TROUBLESHOOTING STRATEGY

Use these steps to plan your diagnostic strategy. If you follow them carefully, you will be sure to find most of the fuel supply faults.

1. Gather information from the customer.
2. Verify that the condition described by the customer exists.
3. Find the malfunction by following the Symptom Chart. Refer to «SYMPTOM CHART»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) .
4. Verify malfunction is eliminated.

Scheme 44

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)

1. Fuel injector failed.
2. Open or shorted fuel injector circuit, or loose connector.
3. Bent, twisted or clogged fuel pipe or hose.
4. Malfunction of the fuel pump module.

DIAGNOSIS

Required Special Tools

1. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: V.C.I. MB991827: USB Cable MB991911: Main Harness B
2. MB991637: Fuel Pressure Gauge Set
3. MD998709: Adaptor Hose
4. MD998742: Hose Adaptor

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1. STEP 1. Using scan tool MB991958, read the diagnostic trouble code (DTC). CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. Ensure that the ignition switch is at the "LOCK" (OFF) position. Start up the personal computer. Connect special tool MB991827 to special tool MB991824 and the personal computer. Connect special tool MB991911 to special tool MB991824. Connect special tool MB991911 to the data link connector. Turn the power switch of special tool MB991824 to the "ON" position. NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color. Start the MUT-III system on the personal computer. Turn the ignition switch to the "ON" position. Check for MFI system diagnostic trouble code. (refer to «HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/testing-diagnostics/#multiport-fuel-injection-20l-evolution) ). Turn the ignition switch to the "LOCK" (OFF) position. Q: Is any DTC set? YES: Remove scan tool MB991958 in a reverse of the installation procedure. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/testing-diagnostics/#multiport-fuel-injection-20l-evolution). NO: Go to Step 2.
2. STEP 2. Check the fuel pressure. Release residual pressure from the fuel line to prevent fuel spray. (Refer to «FUEL PUMP CONNECTOR DISCONNECTION (HOW TO REDUCE PRESSURIZED FUEL LINES)»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/testing-diagnostics/#multiport-fuel-injection-20l-evolution) ). CAUTION: To prevent a fire, cover the hose connection with shop towels to prevent splashing of fuel that could be caused by some residual pressure in the fuel pipe line. Disconnect the fuel high-pressure hose at the fuel rail side. Assemble the fuel pressure measurement tools as follows. When using the fuel pressure gauge Remove the union joint and bolt from special tool MD998709 (adaptor hose) and instead attach special tool MD998742 (hose adaptor) to the adaptor hose. Place a suitable O-ring or gasket on assembled special tools MD998709 and MD998742 and install the fuel pressure gauge. Install the assembled fuel pressure measurement tools between the fuel rail and fuel high-pressure hose. When using the special tool MB991637 (fuel pressure gauge set) Remove the union joint and bolt from special tool MD998709 (adaptor hose) and instead attach special tool MD998742 (hose adaptor) to the adaptor hose. Install special tool MB991637 (fuel pressure gauge set) to assembled special tools MD998709 and MD998742 with a gasket. Install the assembled fuel pressure measurement tools between the fuel rail and the fuel high-pressure hose. Turn the ignition switch to the "ON" position. Use scan tool MB991958, check the MFI system Actuator test 07 to drive the fuel pump. Check that there is no fuel leaking from any section when the fuel pump is operating. Stop the fuel pump. Start the engine and run at idle. Measure fuel pressure while the engine is running at idle. Standard value: Approximately 230 kPa (33 psi) at curb idle Disconnect the vacuum hose from the fuel pressure regulator and measure fuel pressure with the hose end closed with your finger. Standard value: 289 - 309 kPa (42 - 45 psi) at curb idle Check to see that fuel pressure at idle does not drop even after the engine has been revved several times. Revving the engine repeatedly, hold the fuel return hose lightly with your fingers to feel that fuel pressure is present in the return hose. NOTE: If the fuel flow rate is low, there will be no fuel pressure in the return hose. If any of fuel pressure measured in steps 10 to 13 is out of specification, troubleshoot and repair according to the figure below. Stop the engine and observe fuel pressure gauge reading. It is normal if the reading does not drop within two minutes. If it does drop, observe the rate of droppage and troubleshoot and repair according to the figure (Scheme 50) below. Start, then stop the engine. Squeeze the fuel return line closed to confirm leak-down occurs from defective fuel pressure regulator. Squeeze the fuel supply line closed to confirm leak-down occurs from defective fuel pump check valve. If pressure continues to drop with both fuel lines squeezed closed, fuel injector(s) are leaking. Release residual pressure from the fuel pipe line. (Refer to «FUEL PUMP CONNECTOR DISCONNECTION (HOW TO REDUCE PRESSURIZED FUEL LINES)»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/testing-diagnostics/#multiport-fuel-injection-20l-evolution).) WARNING: Cover the hose connection with shop towels to prevent splash of fuel that could be caused by some residual pressure in the fuel pipe line. Remove the fuel pressure gauge or special tool MB991637, and special tools MD998709 and MD998742 from the fuel rail. Replace the O-ring at the end of the fuel high-pressure hose with a new one. Fit the fuel high-pressure hose into the fuel rail and tighten the bolts to specified torque. Tightening torque: 5.0 +/- 1.0 N.m (44 +/- 9 in-lb) Check for fuel leaks. Use scan tool MB991958 to operate the fuel pump. Check the fuel line for leaks, and repair as needed. Turn the ignition switch to the "LOCK" (OFF) position. Q: Are the fuel pressure test in good condition? YES: Go to Step 3. NO: Remove scan tool MB991958 in a reverse of the installation procedure. Repair or replace damage parts. Then go to STEP 6.
3. STEP 3. w. Q: Are the fuel pipe and hose in good condition? YES: Go to Step 4. NO: Remove scan tool MB991958 in a reverse of the installation procedure. Repair or replace the damage fuel pipe or hose. Then go to STEP 6.
4. STEP 4. Check the fuel pump module operation. Turn the ignition switch to the "ON" position. Check the operating of the fuel pump by using scan tool MB991958 to force-drive the fuel pump. If the fuel pump will not operate, check by using the following procedure. If normal, check the fuel pump drive circuit. Turn the ignition switch to the "LOCK" (OFF) position. Remove the rear seat assembly. (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ). Remove the service hole cover. Disconnect the fuel pump module connector. When the fuel pump drive connector is attached directly to the battery, check if the sound of the fuel pump operation can be heard. NOTE: As the fuel pump is an in-tank type, the fuel pump sound is hard to hear. Remove the fuel tank filler tube cap and check from the tank inlet. Check for fuel pressure by pinching the fuel hose with fingertips. Connect the fuel pump module connector. Install the service hole cover. Install the rear seat assembly. (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ). Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation. Q: Is the fuel pump module operation in good condition? YES: Then go to Step 5. NO: Replace the fuel pump module (Refer to «FUEL PUMP MODULE REPLACEMENT»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) ). Then go to STEP 6.
5. STEP 5. Check the inside of the fuel tank for contamination and rust. Drain fuel. Remove the fuel tank. (Refer to «REMOVAL AND INSTALLATION»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) ). Check the inside of the fuel tank. Q: Is the fuel tank in good condition? YES: Install the fuel tank. (Refer to «REMOVAL AND INSTALLATION»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) ). Go to Step 6 NO: Replace the fuel filter, and clean the fuel tank and fuel line. Then go to Step 6.
6. STEP 6. Retest the system. Q: Is the engine malfunction eliminated? YES: Finish. NO: Return to STEP 1.

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FUEL PUMP OPERATION CHECK

Refer to ON-VEHICLE SERVICE .

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1. Remove the rear seat cushion assembly. (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ).
2. Remove the service hole cover.
3. Disconnect the harness connector. NOTE: Check the fuel pump (Refer to «ON-VEHICLE SERVICE»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/testing-diagnostics/#multiport-fuel-injection-20l-evolution) ). If defective, replace the fuel pump, which is incorporated in the fuel pump module.
4. Disconnect fuel high-pressure hose, suction hose and fuel return hose. CAUTION: When withdrawing the fuel pump module from the fuel tank, be careful not damage the module unit and the float.
5. Unscrew the mounting nuts to remove the fuel pump module.
6. Replace the fuel pump (Refer to «FUEL PUMP MODULE DISASSEMBLY AND ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) ). CAUTION: When installing the fuel pump module into the fuel tank, be careful not damage the module unit and the float.
7. Install the fuel pump module. Tighten the mounting nuts to the specified torque. Tightening torque: 2.5 +/- 0.5 N.m (23 +/- 4 in-lb) CAUTION: Snap the fuel high-pressure hose one-touch joint into place, then pull back slightly on the hose to assure it is secure. However, the connection should have a play of approximately 3.0 mm (0.12 inch).
8. Connect the harness connector, fuel high-pressure hose, suction hose and fuel return hose.
9. Replace the service hole cover.
10. Install the rear seat cushion assembly (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ).

FUEL LEVEL SENSOR CHECK

Refer to ON-VEHICLE SERVICE .

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1. Remove the rear seat cushion assembly. (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ).
2. Remove the service hole cover.
3. Disconnect the harness connector, fuel high-pressure hose, suction hose and fuel return hose. CAUTION: When withdrawing the fuel pump module or fuel pipe and gauge assembly from the fuel tank, be careful not damage the sensor unit and the float.
4. Unscrew the mounting nuts to remove the fuel pump module or fuel pipe and gauge assembly. NOTE: Check the fuel level sensor (Refer to «ON-VEHICLE SERVICE»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/gauges-instrument-panels/#combination-meter-vehicle-speed-sensor-evolution) ). If defective, replace it. (Refer to «FUEL PUMP MODULE DISASSEMBLY AND ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/fuel-system/#fuel-supply-evolution) ). CAUTION: When inserting the fuel pump module or fuel pipe and gauge assembly into the fuel tank, be careful not damage the sensor unit and the float.
5. Install the fuel pump module or fuel pipe and gauge assembly. Tighten the mounting nuts to the specified torque. Tightening torque: 2.5 +/- 0.5 N.m (23 +/- 4 in-lb) CAUTION: Snap the fuel high-pressure hose one-touch joint into place, then pull back slightly on the hose to assure it is secure. However, the connection should have a play of approximately 3.0 mm (0.12 inch).
6. Connect the harness connector, fuel high-pressure hose, suction hose and fuel return hose.
7. Replace the service hole cover.
8. Install the rear seat cushion assembly. (Refer to «REAR SEAT ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/seats/#rear-seat-assembly-evolution) ).

Scheme 64

1. Place a drain pan, and disconnect the fuel filler neck breather hose at pipe side. NOTE: If fuel leaks from the fuel filler neck breather hose at this stage, the fuel tank leveling valve may be defective.
2. Open the fuel tank filler cap, and fill the fuel tank up.
3. If fuel does not leak from the fuel tank filler neck breather hose with the fuel tank full, the fuel tank leveling valve is normal. If not so, the fuel tank leveling valve may be defective. Lower the fuel tank from the vehicle and replace the fuel tank leveling valve.
4. Reconnect the fuel filler neck breather hose at the pipe side.

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Required Special Tool

1. MB991348: Test Harness Set

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1. Remove the differential support member and tilt the differential carrier. (Refer to «DIFFERENTIAL CARRIER ASSEMBLY»(/mitsubishi/lancer-evolution/viii-2003-2005/remont/differentials-drive-axles/#rear-axle-evolution) ).
2. Hold the fuel tank assembly with a transaxle jack and remove the nuts connected to the fuel tank assembly.
3. Remove the fuel tank assembly in the tilting direction to avoid contact with the differential carrier.

<< B >> FUEL PIPE AND GAUGE ASSEMBLY/FUEL PUMP MODULE REMOVAL

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>> A << FUEL PUMP MODULE/FUEL PIPE AND GAUGE ASSEMBLY INSTALLATION

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>> B << FUEL HIGH-PRESSURE HOSE INSTALLATION

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>> A << O-RING/GROMMET INSTALLATION

Apply gasoline on the O-ring and the grommet before mounting them to prevent damage or twisting.

FUEL SHUT-OFF VALVE CHECK

Check that the flapper of the fuel shut-off valve opens and closes (Scheme 73)

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1. Shake the fuel tank rollover valve assembly up and down to check the float inside the fuel tank rollover valve assembly is not seized.
2. Obtain a container, which is full of water.
3. Invert the fuel tank rollover valve assembly, and submerge it slowly in the water while placing your fingers over the nozzle.
4. Check that no more air bubbles appears from the fuel tank rollover valve assembly, and withdraw it slowly.
5. Open the fuel tank rollover valve assembly nozzle. If no water flows out from the nozzle aperture, the valve is normal. If water flows out, the float or spring inside the fuel tank rollover valve is defective. Replace the fuel tank rollover valve assembly.

FUEL TANK DIFFERENTIAL PRESSURE SENSOR CHECK

1. Disconnect the fuel tank differential pressure sensor connector and connect special tool MB991348 between the terminals of the disconnected connector.
2. Turn the ignition switch to "ON" and measure the output voltage between terminals 2 and 3.

1. Standard value: 2.0 - 3.0 V

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FASTENER TIGHTENING SPECIFICATIONS

Identifying Fastener Tightening Specifications

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See also:
• HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE
• REAR SEAT ASSEMBLY
• ON-VEHICLE SERVICE
• DIFFERENTIAL CARRIER ASSEMBLY
• SYMPTOM CHART