Fuel Pump Flow/Pressure Check

Fig. 5 Inertia switch location:

1. Disconnect electrical connector at inertia switch.
2. Crank engine for 15 seconds to reduce fuel pressure in lines.
3. Disconnect fuel line at pressure regulator Fuel system remains pressurized after vehicle is shut down and maintains pressure for a long period of time.
4. Connect hose from fuel return fitting to a two quart container.
5. Attach fuel pressure gauge T80L-9974-B or equivalent to the schraeder valve fitting on fuel rail, then connect jumper wire to circuit 9-25 black/red at VIP test connector Fig. 3.
6. Turn ignition switch to run Do not start vehicle. Connect jumper to ground for one minute while observing pressure gauge, then disconnect ground and observe pressure gauge.
7. Check volume of fuel in container.
8. The fuel pump is operating properly if all three conditions are met:
a. Fuel pump pressure reaches 43.5 psi.
b. Fuel flow is a minimum of 1.8-1.9 quarts in one minute.
c. Fuel pressure remains at a minimum of 30 psi immediately after shut down.
9. If pressure condition is met, but flow condition is not, check for blocked filters or blocked fuel lines.
10. If both pressure and flow conditions are met but pressure will not maintain after shut down, check for leaking injectors or pressure regulator.