Fuel Pressure Regulator
- Ensure ignition is off. Connect fuel pressure gauge to Schrader valve on fuel rail. Ensure manifold vacuum supply tube is connected to fuel pressure regulator. Start engine and run for 10 seconds. Stop engine and wait 10 seconds. Start engine and operate for 10 seconds. Stop engine. Remove pressure regulator vacuum hose. Check vacuum port for fuel.
- If fuel is present, replace fuel pressure regulator and repeat test. If fuel is not present, start engine and run for 30 seconds. Stop engine. Check fuel pressure gauge. If pressure does not drop, go to step 4). If pressure drops more than 5 psi (34 kPa) in 60 seconds, disconnect and plug fuel return line at engine. Cycle ignition on and off until normal fuel pressure is obtained.
- Turn ignition off. Check fuel pressure gauge. If pressure drops more than 5 psi (34 kPa) in 30 seconds, replace fuel pump assembly. If pressure does not drop more than 5 psi (34 kPa) in 30 seconds, replace fuel pressure regulator.
- Ensure ignition 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 vacuum. 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.