VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. Inspect air induction system for possible vacuum leaks. Check for fuel leaks.
FUEL PRESSURE TEST
Note. Check fuel system pressure only when fuel cylinders are at least half full.
Remove engine cover. Remove air filter. Remove service port cap from fuel rail. Attach 0-300 psi pressure gauge to service port. Start engine and allow to reach operating temperature. Pressure should be 110-125 psi. Factors affecting pressure are
- Regulator
- Engine temperature
- Ambient temperature
- Low pressure fuel shut-off solenoid condition
- Fuel injector condition
- High pressure fuel shut-off solenoid condition
- Engine load requirements
If pressure is more than 125 psi with cylinders more than half full and engine at operating temperature, replace fuel pressure regulator. If presure is less than 110 psi, check fuel level, all 4 fuel control valves are fully open, manual fuel shut-off valve is open and fuel lines for kinks or bends. Check low pressure fuel shut-off solenoid, high pressure fuel shut-off solenoid and fuel injectors. See SYSTEM & COMPONENT TESTING - RWD VANS - CNG article. After test is complete, remove test gauge. Install service port cap and check system for leaks. Install air filter and engine cover.
NO-START TESTING PROCEDURES
For additional information on no-start testing procedures, see NS-SEL in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.