Discharge Pressure Test

Fig. 79 Pressure regulator test specification chart.:

1. With engine running, disconnect fuel pump relay.
2. After engine stalls, crank engine two or three times to insure that fuel pressure is reduced to zero.
3. Make sure ignition switch is in OFF position and reconnect fuel pump relay.
4. Connect a fuel pressure gauge between fuel pipe and fuel hose to fuel filter.
5. Start engine and read fuel pressure. Pressure at idle should be 30 psi. Quickly depress and release accelerator pedal. The moment pedal is fully depressed, fuel pressure should read 37 psi. Turn ignition switch to OFF position.
6. On 1982-84 models, disconnect fuel pressure regulator hose from intake manifold.
7. Connect vacuum hose to a variable vacuum source such as Kent Moore J23738 or equivalent
8. Disconnect wiring harness connector at alternator field and oil pressure switch.
9. Turn ignition switch to ON position and operate vacuum pump to achieve specifications in Fig. 79.
10. Fuel pressure readings should correspond to specifications for specific vacuum readings, Fig. 79. If readings are not within specifications, replace regulator, and retest pump. If readings are still not within specifications, replace fuel pump.