Low Pressure Pump Regulator
- Check pressure regulator vacuum lines and hoses for proper connection, cracks, blockage. Disconnect No. 1 vacuum hose from pressure regulator. Connect a vacuum gauge to hose.
- Start engine. Allow engine to idle. Check for vacuum. Vacuum should be present. If no vacuum is present, check vacuum port, vacuum lines and hoses. If vacuum port, lines and hoses are all good, replace solenoid valve.
- Stop engine, then restart engine. Check for vacuum again. No vacuum should be present. If vacuum is present, replace solenoid valve. Stop engine. Connect fuel pressure gauge to service port of fuel filter.
- Start engine. Check that fuel pressure increases when No. 1 vacuum hose is disconnected from regulator. Fuel pressure should be 36-41 psi (2.55-2.85 kg/cm2 ).
- If fuel pressure does not increase to specification, lightly pinch return hose. If pressure still does not increase, replace pressure regulator.