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Home >> Jeep >> 1996 >> Grand Cherokee Limited, 5.2 Y >> Repair and Diagnosis >> External Pages >> Different car >> Section 180 (Engine Controls - Tests W/Codes - 4.0L) >> No-Start Tests >> Test NS-4A - Correcting Fuel Delivery

Test NS-4A - Correcting Fuel Delivery

WARNING: This page is about a different car, the 1995 Jeep Wrangler, 1995 Jeep Grand Cherokee, and 1995 Jeep Cherokee. 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 in this article.
NOTE: Perform TEST NS-2A  before proceeding with this test. For connector terminal identification, see CONNECTOR IDENTIFICATION  at beginning of article. For wiring diagrams, see WIRING DIAGRAMS  . Perform TEST VER-1A  after each repair.
  1. On XJ and YJ bodies, go to next step. On ZJ body, inspect fuel filter and fuel lines from fuel pump module in fuel tank to fuel rail for restrictions. Repair restricted fuel filter or fuel lines. If no restrictions are found, replace fuel pressure regulator and primary filter in fuel pump module located in fuel tank.
  2. Record fuel pressure reading obtained during TEST NS-2A  . Turn ignition off. Release fuel pressure. See FUEL PRESSURE RELEASE  procedure in this article. Remove fuel pressure gauge from fuel rail test port. Install fuel pressure gauge between fuel tank and fuel filter. Turn ignition on.
  3. Using scan tool, run ASD fuel system actuation test. Record fuel pressure. Compare fuel pressure with pressure obtained during TEST NS-2A. If fuel pressure is at least 10 psi (.7 kg/cm2 ) more, go to next step. If fuel pressure is not at least 10 psi (.7 kg/cm2 ) more, go to step 5).
  4. Turn ignition off. Inspect fuel lines between fuel filter and fuel rail for restriction. Repair as necessary. If no restrictions are observed, replace fuel filter.
  5. Turn ignition off. Release fuel pressure. See FUEL PRESSURE RELEASE  procedure in this article. Disconnect fuel return hose at fuel rail. Connect a 6-foot fuel hose to fuel rail return line. Put other end of 6-foot hose into an approved gasoline container with at least a 2-gallon capacity. Go to next step.
    CAUTION: DO NOT  allow fuel pressure to exceed 70 psi (4.9 kg/cm2 ) when squeezing fuel return hose.
  6. Turn ignition on. Using scan tool, actuate fuel system. Gently squeeze fuel return hose and monitor fuel pressure gauge. Using scan tool, stop fuel system actuation. If fuel pressure exceeded 34 psi (2.3 kg/cm2 ), replace fuel pressure regulator. If fuel pressure did not exceed 34 psi (2.3 kg/cm2 ), replace fuel pump and sock filter.
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