Possible Causes & Corrections
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 GMC Sonoma, 2003 GMC Safari, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
Check for the following items:
- Check fuel pressure. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.
- Inspect Throttle Position (TP) sensor for binding or sticking. Voltage should increase at a steady rate as the throttle moves toward Wide Open Throttle (WOT) position.
- Inspect Manifold Absolute Pressure (MAP) sensor response and accuracy. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.
- Check the canister purge system for proper operation.
- Perform fuel injector coil test. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.
- Perform fuel injector balance test. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.
- Test for low fuel pressure after a cold start or during a moderate or full throttle acceleration.
- Check for damaged spark plug wires.
- Inspect for fouled spark plugs.
- Inspect for proper ignition system performance.
- Search for Service Bulletins for calibration updates.
- Test generator output voltage.
- Inspect for a restricted exhaust. See EXHAUST SYSTEM BACKPRESSURE under CYLINDER MECHANICAL INSPECTION under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES - 4.3L ASTRO, BLAZER, JIMMY CANADIAN, SAFARI, SONOMA & S10 PICKUP article.