Fuel Pressure Inspection
WARNING:
Inspect fuel system for leaks or damage before testing fuel pump.
NOTE:
Fuel pump will only operate for about 8 seconds when Output Test Mode is selected and activated.
- Release fuel pressure. See FUEL PRESSURE RELEASE . Install fuel pressure gauge. Turn ignition switch on. Connect scan tool to DLC. Select PCM, active command modes, output test mode and fuel pump PID. Press MODE to change to ALL ON mode. Press START, to run fuel pump. Compare fuel pressure reading on fuel pressure gauge with specifications in FUEL PRESSURE SPECIFICATIONS table.
- If fuel pressure is to high, replace fuel pump. If fuel pressure is to low, on Tribute, go to next step. On B2300, B3000 and B4000, go to step 4 .
- Start engine and let run for 10 seconds. Turn ignition switch off. Restart engine and let run for 10 seconds. Turn ignition switch off. Remove vacuum hose from pressure regulator or damper and check for fuel in hose or pulse damper. If fuel is not present, go to next step. If fuel is present, replace fuel pulse damper.
- Release fuel system pressure and check for restriction in fuel supply line (blockage, kinked or pinched). Using regulated air pressure of 3-5 psi, blow air through fuel supply line. If air flows freely, replace fuel pump. If air does not flow freely, repair restriction as necessary.
FUEL PRESSURE SPECIFICATIONS
| Application | Pressure psi (kg/cm2 ) |
|---|---|
| B2300, B3000 & B4000 | 56-72 (4.0-5.1) |
| Tribute | 55-70 (2.5-4.5) |