Test NTC-5: Checking Engine Vacuum

Connect vacuum gauge at vacuum source on intake manifold. Start engine and allow engine to idle for at least one minute. Note vacuum reading with engine idling and when throttle is quickly opened. Engine vacuum should be at 13 in. Hg with transmission in Neutral with engine idling. If engine vacuum is okay, test is complete. If engine vacuum is not as specified, check for vacuum leaks. Repair vacuum leaks as necessary.