Fuel System Checks
WARNING: This page is about a different car, the 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
- Determine if the condition is rich or lean by operating the vehicle under the conditions of the concern while monitoring the oxygen sensor output.
- Check for leaking fuel injectors.
- Check for fuel in the fuel pressure regulator vacuum hose, if equipped. This indicates a faulty gasoline fuel pressure regulator.
- Check for proper operation of the CNG fuel injectors. See FUEL INJECTOR COIL TEST , FUEL INJECTOR BALANCE TEST WITH SPECIAL TOOL and FUEL INJECTOR BALANCE TEST WITH TECH 2 under FUEL SYSTEMS (CNG) in SYSTEM & COMPONENT TESTS - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article.
- Check for proper EVAP Purge system operation.
- Check for proper alternative fuel system pressures. See FUEL SYSTEM DIAGNOSIS (CNG) under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article.