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Test NS-1A - Inspecting Fuel System

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: Perform VISUAL INSPECTION  in this article before proceeding.
  1. Turn ignition off. Ensure fuel cylinders are at least 1/4 full. Check position of manual shutoff valve. If manual shutoff valve is closed, open valve. Perform TEST VER-1. If manual shutoff valve is open, check position of all fuel cylinder manual control valves. Fuel cylinder manual control valves should be fully counterclockwise when they are open.
  2. If fuel cylinder manual control valves are closed, open valves. Perform TEST VER-1. If fuel cylinder manual control valves are open, turn ignition on. Using scan tool, actuate Auto Shutdown (ASD) relay. Touch ASD relay. If ASD relay is not pulsating, go to TEST NS-2A.
  3. If ASD relay is pulsating, touch fuel shutoff relay. If fuel shutoff relay is not pulsating, go to TEST NS-2B. If fuel shutoff relay is pulsating, touch low pressure fuel shutoff solenoid. If low pressure fuel shutoff solenoid is not pulsating, go to TEST NS-2C. If low pressure fuel shutoff solenoid is pulsating, touch high pressure fuel shutoff solenoid.
  4. If solenoid is not pulsating, go to TEST NS-2D. If solenoid is pulsating, ensure fuel gauge indicates fuel is present. Using scan tool, read fuel pressure. If pressure is less than 90 psi, go to TEST NS-1B. If pressure is 90-134 psi, go to step 6). If pressure is more than 134 psi, go to next step.
  5. Release fuel pressure. If vehicle is equipped with fuel rail test port, connect a 0-300 psi fuel pressure test gauge to test port. On vehicles not equipped with fuel rail test port, 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.
  6. On all models, using scan tool, actuate fuel system. If fuel pressure is more than 140 psi, turn ignition off. Replace fuel pressure regulator. Perform TEST VER-1. If fuel pressure is less than 90 psi, stop actuation test using scan tool. On vehicles not equipped with fuel rail test port, release fuel pressure. Reinstall CNG low pressure sensor.
  7. On all models, ensure throttle is not being held open. If throttle is held open, repair condition causing throttle to be held open. Perform TEST VER-1. If throttle is not held open, read Throttle Position (TP) sensor voltage using scan tool. If voltage is less than 1.5 volts, go to step 9).
  8. If voltage is more than 1.5 volts, turn ignition off. Disconnect and inspect TP sensor connector for damaged, pushed-out or miswired terminals. Repair connector as necessary. Perform TEST VER-1. If connector is okay, replace TP sensor. Perform TEST VER-1.
  9. Disconnect fuel injector No. 1 connector. Using scan tool, actuate fuel system. Using scan tool in voltmeter mode, check voltage on fuel injector No. 1 connector, ASD relay output circuit (Dark Green/Orange wire). If voltage is less than 10 volts, repair open in Dark Green/Orange wire. Perform TEST VER-1.
  10. If voltage is more than 10 volts, reconnect injector connector. Disconnect CNG low pressure shutoff solenoid connector. Using scan tool, immediately read fuel pressure. If fuel pressure is less than 10 psi, go to next step. If fuel pressure is more than 10 psi, reconnect CNG low pressure shutoff solenoid connector. go to TEST NS-4A.
  11. Using scan tool, stop actuation test. Reconnect low pressure fuel shutoff solenoid connector. Using scan tool, actuate fuel system. Using scan tool, stop actuation test. Using scan tool, immediately read fuel pressure. If fuel pressure is more than 10 psi, go to TEST NS-3A.
  12. If fuel pressure is less than 10 psi, remove air cleaner assembly. Using scan tool, actuate fuel system. Hold throttle open and listen for escaping gas. If escaping gas is heard from throttle area, turn ignition off. Release fuel pressure. Repair leaking fuel injector. Perform TEST VER-1.
  13. If escaping gas is not heard from throttle, fuel leak has been isolated to fuel rail area. Turn ignition off. Release fuel pressure. Repair fuel rail as necessary. Perform TEST VER-1.
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