Fuel Pressure Regulator
- Ensure key is off. Connect fuel pressure gauge to Schrader valve on fuel rail. Ensure manifold vacuum supply tube is connected to fuel pressure regulator. Start and run engine for 10 seconds. Stop engine and wait 10 seconds. Start and operate engine for 10 seconds. Stop engine and remove pressure regulator vacuum hose. See Fig 1
. Check vacuum port for fuel.
Courtesy of FORD MOTOR CO.
- If fuel is present, replace fuel pressure regulator and repeat test. If fuel is not present, start and run engine for 30 seconds. Stop engine and check fuel pressure gauge. If fuel pressure does not drop, go to step 4). If fuel pressure drops more than 5 psi (.4 kg/cm2
) in 60 seconds, disconnect and plug fuel return line at engine. Cycle ignition key on and off until normal fuel pressure is obtained.
- Turn key off and check fuel pressure gauge. If gauge drops more than 5 psi (.4 kg/cm2
) in 30 seconds, replace high pressure fuel pump (dual pump system) or fuel sender/pump assembly (single pump type). If gauge does not drop more than 5 psi (.4 kg/cm2
) in 30 seconds, replace fuel pressure regulator.
- Ensure key is off. Relieve fuel pressure. Remove fuel pressure regulator. Check "O" ring, gasket and mounting surfaces for cracks, cuts or other damage. Connect vacuum pump to fuel return tube and apply 20 in. Hg. If maximum vacuum loss exceeds 10 in. Hg in 10 seconds, replace regulator. If maximum vacuum loss does not exceed 10 in. Hg in 10 seconds, recheck entire fuel delivery system for cause of fuel pressure loss.