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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 43 (Engine Controls - Tests W/Codes - 8.0L) >> Self-Diagnostic Tests >> Test NTC-3A - Checking Fuel Pressure & Injector Operation

Test NTC-3A - Checking Fuel Pressure & Injector Operation

WARNING: This page is about a different car, the 1995 Dodge Pickup and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: High fuel pressure may be present in fuel lines. Open fuel system with caution. See FUEL PRESSURE RELEASE  procedure.
  1. Release fuel pressure. Connect fuel pressure gauge to fuel rail. Turn ignition on. Using scan tool, actuate fuel system. If fuel pressure is 34-45 psi (2.5-3.3 kg/cm2 ), go to step 4). If fuel pressure is not 34-45 psi (2.5-3.3 kg/cm2 ), record fuel pressure reading. Go to next step.
  2. If pressure is more than 45 psi (3.3 kg/cm2 ), release fuel pressure. Replace filter/regulator. Perform TEST VER-2. If pressure is not more than 45 psi (3.3 kg/cm2 ). Turn ignition off.
  3. Inspect fuel lines for kinked or restricted lines. Release fuel pressure. Repair fuel lines as necessary. Perform TEST VER-2. If no kinked or restricted lines exist release fuel pressure. Remove fuel pressure gauge from fuel rail. Replace filter/regulator assembly. Perform TEST VER-2.
  4. Stop fuel system actuation. Disconnect injector connectors at injectors No. 1, No. 2, No. 3, No. 5, No. 7 and No. 9. Using scan tool, actuate injector No. 4. If injector No. 4 does not click, go to TEST NTC-3B. If injector No. 4 clicks, stop actuation test. Go to next step.
  5. Using scan tool, actuate injector No. 6. If injector does not click, go to TEST NTC-3B. If injector clicks, stop actuation test. Go to next step.
  6. Using scan tool, actuate injector No. 8. If injector does not click, go to TEST NTC-3B. If injector clicks, stop actuation test. Go to next step.
  7. Using scan tool, actuate injector No. 10. If injector does not click, go to TEST NTC-3B. If injector clicks, stop actuation test. Go to next step.
  8. Reconnect injector connectors at injectors No. 1, No. 2, No. 3, No. 5, No. 7 and No. 9. Using scan tool, actuate injectors No. 1, No. 2, No. 3, No. 5, No. 7 and No. 9 in sequence. If any injector does not click when actuated, go to TEST NTC-3B. If each injector clicks when actuated, go to next step.
    WARNING: Keep hands and feet clear of rotating wheels.
  9. Stop actuation test. If vehicle is equipped with manual transmission, go to step 11). Raise vehicle so drive wheels are free to spin. Start engine. Press and hold brake pedal down. Place gear selector in DRIVE position. While monitoring fuel pressure gauge, quickly press and hold gas pedal halfway down for a few seconds. If fuel pressure does not drop to less than 30 psi (2.1 kg/cm2 ), fuel pressure is okay. Test passed.
  10. If fuel pressure drops to less than 30 psi (2.1 kg/cm2 ), return engine to idle. Place gear selector in PARK position. Turn ignition off. Check fuel supply line to fuel rail for kink or restriction. If line is kinked or restricted, release fuel pressure. Replace fuel line. Perform TEST VER-2. If fuel line is okay, release fuel pressure. Replace fuel pump and filter/regulator assembly. Perform TEST VER-2.
  11. Ensure gear selector is in NEUTRAL position. Engage parking brake. Start engine. While monitoring fuel pressure gauge, momentarily press and hold gas pedal to raise engine speed to more than 3000 RPM. If fuel pressure does not drop to less than 30 psi (2.1 kg/cm2 ), fuel pressure is okay. Test passed.
  12. If fuel pressure drops to less than 30 psi (2.1 kg/cm2 ), return engine to idle. Ensure gear selector is in NEUTRAL position. Turn ignition off. Check fuel supply line to fuel rail for kink or restriction. If line is kinked or restricted, release fuel pressure. Replace fuel line. Perform TEST VER-2. If fuel line is okay, release fuel pressure. Replace fuel pump and filter/regulator assembly. Perform TEST VER-2.
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