Vacuum Regulator Valve

Fig. 55 Vacuum regulator valve. V8-350 diesel engine:

EXCEPT 4-137 CALIFORNIA

1. Disconnect vacuum hoses, connect a suitable vacuum gauge to output tube and apply a constant vacuum of 15 inches Hg to valve supply tube, Fig. 55.
2. Vacuum gauge should read 15 inches Hg with throttle at idle and zero at wide open throttle.
3. Disconnect electrical connector to EPR solenoid switch and connect ohmmeter across switch terminals.
4. Open throttle while observing vacuum gauge and ohmmeter. Meter should indicate continuity with vacuum reading above 12 inches Hg and infinite resistance with vacuum reading below 12 inches Hg.
5. If VRV fails to perform as outlined, check adjustment and repeat tests. If operation is still not as specified, VRV is defective.