HC6 - Check Fuel Pressure Regulator Response to Vacuum

- Key Off.

- Fuel pressure tester installed.

- Install vacuum gauge to intake manifold.

- Start engine and observe both gauges.

- Accelerate and decelerate engine speed to vary the vacuum gauge reading.

- Does fuel pressure gauge reading increase as vacuum gauge reading decreases, or does fuel pressure gauge reading decrease as vacuum gauge reading increases?

YES -- REMOVE vacuum gauge and fuel pressure tester. Problem is elsewhere. RETURN to Symptom Flow Charts for further direction. Testing and Inspection

NO -- GO to HC7. HC7 - Check Vacuum Supply