Possible Causes & Corrections
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Check for the following items:
- Ensure driver understands the torque converter clutch operation and A/C compressor operation.
- Ensure that transmission fluid is at proper level.
- Display scan tool parameters for the various engine controls sensors. Inspect for any abnormal readings.
- Inspect for a rich or lean symptom that causes the condition. Drive vehicle at the speed of the complaint. Monitoring the fuel trim will help identify the condition.
- Lean condition. The long term fuel trim will be more than 150 displayed on scan tool.
- Rich condition. The long term fuel trim will be less than 115 displayed on scan tool.
- Check fuel pressure while the condition exists. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4.3L SIERRA & SILVERADO article.
- Inspect in-line fuel filter for restrictions.
- Check for proper ignition output voltage using Spark Tester (J-26792). Inspect spark plugs. Remove plugs and inspect for wetness, cracks, wear, improper gap, burned electrodes or heavy deposits.
- Check the secondary ignition system and spark plugs. Remove plugs and inspect them for wetness, cracks, wear, improper gap, burned electrodes or heavy deposits.
- Check for a loose or damaged Crankshaft Position (CKP) sensor and reluctor wheel.
- Inspect control module grounds for being clean, tight, and in their proper locations.
- Test generator output voltage.
- Inspect vacuum hoses for kinks or leaks.
- Check for an intermittent EGR problem.
- Inspect TCC operation. See appropriate DIAGNOSIS in AUTOMATIC TRANSMISSIONS.
- Inspect exhaust system for a possible restriction. See RESTRICTED EXHAUST .