Test NS-4A - Correcting Fuel Delivery
WARNING:
Fuel system must be opened and may be under high pressure.
- Measure and record fuel pressure gauge reading at fuel rail. Turn ignition off. Remove fuel pressure gauge and reconnect fuel line. Install fuel pressure gauge in fuel line between fuel tank and fuel filter. Turn ignition on. Using DRB-II, actuate ASD fuel system. Record fuel pressure gauge reading.
- Compare fuel pressure gauge readings. If fuel pressure is not at least 10 psi more, go to step 3). If fuel pressure is at least 10 psi more, go to step 4).CAUTION: DO NOT allow fuel pressure to exceed 70 psi.
- Watch fuel pressure gauge while gently squeezing fuel return hose. If fuel pressure is greater than 35 psi, replace fuel pressure regulator. Perform VERIFICATION TEST VER-1 . If fuel pressure is 35 psi or less, replace fuel pump and filter sock assembly. Perform VERIFICATION TEST VER-1 .
- Inspect fuel lines between fuel filter and fuel rail for restriction. If fuel lines are restricted, repair lines as necessary. Perform VERIFICATION TEST VER-1 . If lines are not restricted, replace fuel filter. Perform VERIFICATION TEST VER-1 .