GM Service Manual Online
For 1990-2009 cars only

Checks

Action

DEFINITION: The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but immediately dies.

Preliminary Checks

    • Refer to Symptoms - Engine Controls .
    • Ensure the driver is using the correct starting procedure.

Sensor Checks

    • Inspect the engine coolant temperature (ECT) sensor. Use the scan tool to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, check for a high resistance in the coolant sensor circuit or the sensor itself.
    • Inspect the fuel rail pressure (FRP) sensor. Use the scan tool to observe FRP with the engine OFF. FRP should be near 1.4 MPa. If not , check for high resistance in the low reference, 5-volt reference circuits, or the FRP sensor.

Fuel System Checks

    • Inspect the fuel pressure regulator 12-volt circuit for an intermittent short to ground. Observe the FRP Command percent while cranking. A range of 85-95 percent indicates a possible short to ground condition.
    • Inspect the supply to the fuel injection pump.
    • Inspect for air in the fuel system.
    • Inspect for external fuel leaks or high oil level.
    • Inspect the fuel return from the injection pump.
    • Inspect the fuel injectors.
    • Inspect the fuel tank cap vent.
    • Inspect for an internal fuel injection pump problem.

Electrical System Checks

    • Inspect glow plug operation.
    • Inspect for slow cranking speed.

Air Intake System Checks

    • Inspect the air cleaner and air intake ducts for a restriction, holes, or leaks.
    • Inspect for a restriction in turbo charger inlet duct.
    • Inspect for a restriction or leak in the intake manifold.

Exhaust System Check

Inspect the exhaust system for a possible restriction. Refer to Restricted Exhaust .

Engine Mechanical Checks

Inspect the engine for the following:

    • Improper valve timing
    • Bent pushrods
    • Worn rocker arms
    • Low compression
    • Broken or weak valve springs
    • Worn camshaft lobes

Additional Checks

    • Inspect for an intermittent RPM signal.
    • Inspect the Service Bulletins for control module software updates.