Vacuum advance question ?
Thread Starter
Heel & Toe
Joined: Jan 2006
Posts: 21
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Vacuum advance question ?
I have a 72 with a 350 base motor. It has the q-jet carb. The question is this, I seem to have no vacuum at the distributor . I noticed that there is a type of switching device, with two wires going to it. I do have vacuum going into it. What activates this switching device? And does it come in at a certain RPM for the proper advance?The mechanical advance seem to be working,But at about 3500 RPM it looses power, and starts to break up.Below this RPM it runs great.
Thanks for any input!!!!
Thanks for any input!!!!
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,332
From: At my Bar drinking and wrenching in Lafayette Colorado
The electrical switch is called a TCS for Transmission Controlled Spark. It only allows vacuum advance after the car is in 2nd gear or higher for reduced emissions (by retarding timing). You can bypass the switch and hook up directly to manifld vacum, but this will not cure your 3500rpm power loss - you have something else going on there that you need to correct.
