Fuel System Pressure Test

On RWD vans, remove engine cover. Remove air cleaner assembly. On all models, connect pressure gauge (0-300 psi) to service port on fuel injector rail. Start engine and monitor fuel pressure.
Minimum operating pressure is 90 psi, and maximum operating pressure is 140 psi. Operating pressures can be affected by:
- Outside ambient temperature.
- Low-pressure fuel shutoff solenoid condition.
- Fuel injector(s) condition.
- High-pressure fuel shutoff solenoid and solenoid relay condition.
- Engine load requirements.
If fuel pressure is more than 140 psi (fuel tanks 1/8 full-minimum), replace fuel pressure regulator. Refer to REMOVE/INSTALL/OVERHAUL - 3.3L CNG article in the ENGINE PERFORMANCE section.
If fuel pressure is less than 90 psi, ensure all fuel cylinders are have sufficient fuel level (1/8 or more). Ensure manual shutoff valve and all fuel control valves are fully open. Inspect fuel tubes for kinks and restrictions.
Inspect and test low-pressure fuel shutoff solenoid, high-pressure fuel shutoff solenoid and fuel injectors. Refer to SYSTEM/COMPONENT TESTS - 3.3L CNG article in the ENGINE PERFORMANCE section. Inspect fuel system for leaks. See LEAK TESTING. Remove fuel pressure gauge. On RWD vans, install air cleaner assembly and engine cover.