Fuel Delivery and Air Induction: Testing and Inspection

Vacuum Switch

1. Disconnect electrical connector from vacuum switch and connect an ohmmeter across connector terminals.
2. Start engine and run at idle. Ensure there is no continuity between terminals.
3. Disconnect vacuum line from switch and observe ohmmeter. Continuity should now exist between switch terminals.

Delay Valve

1. Disconnect electrical connector from vacuum switch and connect an ohmmeter across connector terminals.
2. Start engine and accelerate to a steady 3000 RPM for 2-3 seconds.
3. Quickly decrease engine speed and observe ohmmeter. Ohmmeter should indicate continuity between terminals for 3-25 seconds after returning engine to idle.