Fuel System
WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
- Check the fuel system circuits for proper operation. Go to FUEL PUMP ELECTRICAL CIRCUIT DIAGNOSIS (ALERO & GRAND AM) or FUEL PUMP ELECTRICAL CIRCUIT DIAGNOSIS (IMPALA & MONTE CARLO) under FUEL SYSTEMS in SYSTEM & COMPONENT TESTS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
- Check for low fuel pressure. Go to FUEL SYSTEM DIAGNOSIS under FUEL SYSTEMS in SYSTEM & COMPONENT TESTS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
- Check for faulty fuel injectors. Go to FUEL INJECTOR BALANCE TEST WITH SPECIAL TOOL , FUEL INJECTOR BALANCE TEST WITH TECH 2 or FUEL INJECTOR COIL TEST under FUEL SYSTEMS in SYSTEM & COMPONENT TESTS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
- Inspect for fuel contamination. Go to ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITH SPECIAL TOOL or ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITHOUT SPECIAL TOOL under FUEL SYSTEMS in SYSTEM & COMPONENT TESTS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
- Inspect any items which may cause an engine to run rich, long term fuel trim is significantly in the negative range. Go to DIAGNOSTIC AIDS for DTC P0172: FUEL TRIM SYSTEM RICH under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
- Inspect any items which may cause an engine to run lean, long term fuel trim is significantly in the positive range. Go to DIAGNOSTIC AIDS for DTC P0171: FUEL TRIM SYSTEM LEAN under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.