Test NTC-3A - Checking Fuel Pressure
WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, and 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Before any part of Compressed Natural Gas (CNG) fuel system is opened for repair, purge system of all natural gas. See FUEL PRESSURE RELEASE
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- On vehicles equipped with fuel rail test port, connect a 0-300 psi pressure test gauge to test port. On vehicles not equipped with fuel rail test port, purge fuel system. See FUEL PRESSURE RELEASE . Remove Compressed Natural Gas (CNG) low pressure sensor. Connect a 0-300 psi pressure test gauge between CNG low pressure sensor and fuel rail block. Install CNG low pressure sensor to test gauge tee connection. If CNG low pressure sensor is not reinstalled, engine will start, then stall.
- On all models, ensure fuel tank is 1/4 full. Start engine. Allow it to reach normal operating temperature (more than 180°F). If pressure gauge indicates 90-140 psi, go to step 5). If gauge indicates more than 140 psi, replace fuel pressure regulator. Perform TEST VER-2.
- If gauge indicates less than 90 psi, perform following checks to help identify possible fuel delivery mechanical problems. Ensure all cylinders have fuel, all fuel cylinder control valves are opened, manual gas shutoff valve is opened, fuel lines are free of any kinks or bends, and fuel filter is not plugged.
- If any fuel delivery mechanical problems are present, repair fuel delivery system as necessary. Perform TEST VER-2. If fuel delivery mechanical problems are not present, fuel problem has not been located, go to TEST NTC-1A.
- Using scan tool, read fuel pressure. Compare scan tool fuel pressure reading with pressure test gauge reading. If readings are not within 5 psi of each other, replace CNG low pressure sensor. Perform TEST VER-2. If CNG fuel pressure is within 5 psi of pressure test gauge reading, fuel pressure is okay. Test is complete.