Plugging vacuum advance while adjusting timing?
Thread Starter
Burning Brakes
Joined: Oct 2022
Posts: 1,063
Likes: 170
From: Buckeye Lake, OH
Plugging vacuum advance while adjusting timing?
I was talking with a guy at work today about adjusting timing on my car. He said I should put a cap on the vacuum advance module on my distributor when setting timing. My opinion was that capping the vacuum advance was not necessary as there is no negative/positive pressure to effect the advance module. What say you?
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,332
From: At my Bar drinking and wrenching in Lafayette Colorado
You have to disconnect the hose to the vacuum advance when setting timing. Whether or not you "plug" it is irrelevant. Once the hose is disconnected and the vacuum advance is vented to atmospheric pressure it is inoperable and does not affect timing. The unplugged vacuum leak at the carb is also irrelevant to timing and does not need to be plugged to set initial and total timing. The engine may run like crap with the vacuum leak, but this does not affect your timing setting procedure.
Bottom line: You're right. He's wrong. Assuming you are yanking the hose off the vacuum advance to disconnect it from engine vacuum.
Lars
Bottom line: You're right. He's wrong. Assuming you are yanking the hose off the vacuum advance to disconnect it from engine vacuum.
Lars
