Checking Engine Vacuum

Connect vacuum gauge to engine vacuum source. Start engine and allow engine to idle. Note engine vacuum reading. Engine vacuum should be steady and 13-22 in. Hg with engine at idle. While monitoring engine vacuum reading, quickly open and close the throttle several times and then allow engine to idle. If engine vacuum is within specification, test is complete. If engine vacuum is not within specification, check for vacuum leaks and repair as necessary. If no vacuum leaks are found, check for engine mechanical problem.