Possible Causes & Corrections
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Check the following items:
- Verify that driver is using the correct starting procedure as described in the owner's manual.
- Verify that PCM grounds are clean, tight and in the proper locations.
- Search for bulletins.
- Verify that the Engine Coolant Temperature (ECT) sensor is not shifted in value. Using a scan tool, compare the engine coolant temperature to Intake Air Temperature (IAT) on a cold engine. The ECT and IAT sensor values should be within 5°F (3°C) of each other. If ECT sensor is out of range with the IAT sensor, measure the resistance of ECT sensor. See SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - 2.2L SONOMA & S10 PICKUP article.
- Inspect the Camshaft Position (CMP) sensor for proper mounting and/or a bad connection. An extended crank occurs if PCM does not receive a CMP signal.
- Inspect MAP sensor for proper operation. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 2.2L SONOMA & S10 PICKUP article.
- Inspect fuel pump relay operation. Fuel pump should turn on for 2 seconds when you turn on the ignition.
- A faulty in-tank fuel pump check valve allows the fuel in the lines to drain back to the tank after engine stops.
- Inspect fuel injectors. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 2.2L SONOMA & S10 PICKUP article.
- Inspect for incorrect fuel pressure. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 2.2L SONOMA & S10 PICKUP article.
- Inspect for a restricted fuel filter.
- Inspect for a contaminated fuel condition.
- Inspect for proper ignition voltage output with a Spark Tester (J-26792).
- Remove spark plugs and inspect for correct heat range, wet plugs, cracks, wear, improper gap, burned electrodes Heavy deposits
- Determine cause of the conditions before replacing the spark plugs.
- Inspect for bare or shorted ignition wires.
- Check for excessive oil in combustion chamber or leaking valve seals.
- Check for low cylinder compression.
- Check combustion chambers for excessive carbon buildup. Clean chambers using top engine cleaner.
- Check incorrect basic engine parts, i.e. cylinder heads, camshaft, pistons, etc.