Fuel System Checks
- Check for incorrect fuel pressure. See FUEL SYSTEM DIAGNOSIS
under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 2.2L ION article.
- Check the fuel injectors. See FUEL INJECTOR COIL TEST
under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 2.2L ION article.
- Check for a restricted fuel filter. See FUEL SYSTEM DIAGNOSIS
under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 2.2L ION article.
- Check for a contaminated fuel condition. See ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITH SPECIAL TOOL
or ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITHOUT SPECIAL TOOL
under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 2.2L ION article.
- Check that each fuel injector harness is connected to the correct injector and cylinder. Relocate the injector harnesses as necessary.
- Check the following that may cause the engine to run rich:
- Any water intrusion in the HO2S connector.
- Engine oil contaminated by fuel.
- An EVAP canister purge condition.
- Incorrect fuel pressure. See FUEL SYSTEM DIAGNOSIS
under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 2.2L ION article.
- A leaking fuel pressure regulator. See FUEL SYSTEM DIAGNOSIS
under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 2.2L ION article.
- Leaking fuel injectors. See FUEL SYSTEM DIAGNOSIS
under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 2.2L ION article.
- Split, kinked, or improperly connected vacuum hoses.
- Collapsed or restricted air intake duct.
- Dirty or restricted air filter.
- Check the following that may cause the engine to run lean: