GM Service Manual Online
For 1990-2009 cars only

Checks

Action

DEFINITION: The engine cranks normally, but does not start in a normal amount of time. The engine does eventually run, or may start but immediately dies.

Preliminary Checks

    • Refer to Symptoms - Engine Controls .
    • Make sure the vehicle operator is using the correct starting procedure.

Sensor Checks

Check the engine coolant temperature (ECT) sensor with the scan tool. Compare the engine coolant temperature 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 high resistance in the coolant sensor circuit.

Fuel System Checks

    • Check the fuel pump relay for proper operation. The fuel pump should operate for the first 2 seconds when turning ON the ignition. Refer to Fuel Pump Electrical Circuit Diagnosis .
    • Check the fuel pressure. Refer to Fuel System Diagnosis .
    • Check for water contamination in the fuel.
    • Perform the fuel injector coil test. Refer to Fuel Injector Solenoid Coil Test .
    • Perform the fuel injector balance test. Refer to Fuel Injector Balance Test with Tech 2 .
    • Check the fuel pump check valve. Refer to Fuel System Diagnosis .

Ignition System Checks

    • Check the spark plugs for the following conditions:
       - Wet plugs
       - Cracks
       - Wear
       - Improper gap
       - Burned electrodes
       - Heavy deposits
    • Check for loose ignition coil connections.
    • Check for loose ignition control module connections.
    • Check for a faulty control module or ignition system grounds.
    • Check the ignition control (IC) circuit for an open or short to ground.

Engine Mechanical Checks

    • Check for the following conditions:
    • Improper valve timing
    • Low compression
    • Bent pushrods
    • Worn rocker arms
    • Broken or weak valve springs
    • Worn camshaft lobes
    • Proper Cam Phaser operation

Additional Check

Check for a restricted exhaust. Refer to Restricted Exhaust in Engine Exhaust.