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Home >> Chevrolet >> 2002 >> Malibu LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Basic Diagnostic Procedures >> No-Start Diagnosis >> No Start - Engine Cranks Okay (2.2L & 2.4L - ALERO, Cavalier, Grand Am & SUNFIRE) >> Fuel System Diagnosis

Fuel System Diagnosis

NOTE: Inspect fuel system for damage or external leaks before proceeding with this diagnostic.
  1. If diagnostic system check has already been performed, go to next step. If diagnostic system check has not been performed, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS in appropriate SELF-DIAGNOSTICS article.
  2. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on. Does fuel pump operate? If yes, go to next step. If no, go to FUEL PUMP ELECTRICAL CIRCUIT .
    3. NOTE: Verify that adequate fuel is in fuel tank before proceeding with this diagnostic.
  3. Turn ignition and all accessories off. Install a fuel pressure gauge. Turn ignition on, with engine off. Fuel pump relay may need to be commanded ON a few times in order to obtain the highest possible fuel pressure. DO NOT start engine. Command fuel pump relay on using scan tool. Observe fuel pressure gauge with fuel pump commanded on. Is fuel pressure within 50-60 psi (3.5-4.2 kg/cm2 ). If yes, so to next step. If no, go to step  10.
  4. Monitor fuel pressure gauge for one minute. Does fuel pressure decrease by more than 5 psi (0.4 kg/cm 2 ). If yes, go to step  7. If no, go to next step.
  5. Relieve fuel pressure to 10 psi (0.7 kg/cm 2 ). Monitor fuel pressure gauge for 5 minutes. Does fuel pressure decrease by more than 2 psi (0.1 kg/cm 2 )? If yes, go to step  20. If no, go to next step.
  6. Operate vehicle within the conditions to reproduce the original symptoms. Monitor O2 and Fuel Trim parameters with scan tool. Does scan tool parameters indicate a lean condition? If yes, go to step  13. If no, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article.
  7. Turn ignition off. Remove hose from fuel pressure regulator. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on. Inspect for fuel leak from fuel pressure regulator port. Is fuel pressure regulator leaking fuel? If yes, go to step  19. If no, go to next step.
  8. Turn ignition off. Relieve fuel pressure. Disconnect the chassis fuel hoses from engine compartment fuel pipes. Install Fuel Line Shut-off Adapters (J-37287) between chassis fuel hoses and engine compartment fuel pipes. Open the valves on the fuel pipe shut-off adapters. Turn ignition on, with engine off. Command fuel pump relay on with scan tool. Bleed air from fuel pressure gauge. Command fuel pump relay on and then off with scan tool. Close fuel feed pipe shut-off valve. Monitor fuel pressure gauge for one minute. Does fuel pressure remain constant? If yes, go to step  16. If no, go to next step.
  9. Turn ignition off. Open fuel feed pipe shut-off valve. Turn ignition on, with engine off. Command fuel pump relay on and then off with scan tool. Close fuel return pipe shut-off valve. Monitor fuel pressure gauge for one minute. Does fuel pressure remain constant? If yes, go to step  19. If no, go to step  17.
  10. Is fuel pressure more than 60 psi (4.2 kg/cm2 )? If yes, go to next step. If no, go to step  13.
  11. Turn ignition off. Relieve fuel pressure. Disconnect fuel return hose from engine compartment fuel return pipe. Place open end of flexible fuel return hose into an approved gasoline container. Turn ignition on, with engine off. Monitor fuel pressure gauge while fuel pump is operating. Is fuel pressure within 50-60 psi (3.5-4.2 kg/cm2 )? If yes, go to step  18. If no, go to next step.
  12. Inspect fuel rail return pipe and fuel rail outlet passage for a restriction. Did you find and correct the condition? If yes, go to step  21. If no, go to step  19.
  13. Turn ignition off. Relieve fuel pressure. Disconnect fuel return hose from engine compartment fuel return pipe. Install Fuel Line Shut-off Adapter (J-37287) between the fuel return hose and engine compartment fuel pipe. Open valve in fuel pipe shut-off adapter. Turn ignition on, with engine off. Bleed air from fuel pressure gauge. Monitor fuel pressure gauge. DO NOT allow fuel pressure to exceed 75 psi (5.27 kg/cm 2 ). Excessive pressure may damage fuel system. Using scan tool, command fuel pump relay on. Slowly close valve in fuel return pipe shut-off adapter, while fuel pump is operating. Does fuel pressure increase to more than 60 psi (4.2 kg/cm2 )? If yes, go to step  19. If no, go to next step.
  14. Inspect for a restricted fuel filter or fuel feed pipe. Did you find and correct the condition? If yes, go to step  21. If no, go to next step.
  15. Inspect harness connectors and ground circuits of fuel pump for poor connections. Did you find and correct the condition? If yes, go to step  21. If no, go to next step.
  16. Remove fuel sender assembly. Inspect fuel pump flex hose for damage, in-tank fuel pump harness connectors for poor connections, fuel strainer for a restriction or fuel tank for contaminants. Did you find and correct the condition? If yes, go to step  21. If no, go to step  20.
  17. Open the fuel return pipe shut-off valve. Turn ignition off. Raise fuel rail, with fuel lines connected. Turn ignition on, with engine off. Command fuel pump relay on with scan tool. Locate and replace leaking fuel injector. After repairs, go to step  21.
  18. Repair restricted fuel return pipe. After repairs, go to step  21.
    19. NOTE: Inspect for a missing or damaged "O" ring seal before replacing fuel pressure regulator.
  19. Replace fuel pressure regulator. After repairs, g to step  21.
  20. Replace fuel sender. After repairs, go to next step.
  21. Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step  3.
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