Muncie TCS switch question - Chevelle Tech
Transmission & Driveline Transmissions and Differentials

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post #1 of 3 (permalink) Old Apr 20th, 10, 9:00 PM Thread Starter
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Muncie TCS switch question

Ok boys and girls, Ive got a trick question...

So Ive done a little research on this little fitting [that I broke] wich sits in the side cover of my M21, directly beneath the 3/4 shaft hole.

So this thingamijig is called a "TCS" switch and in some way shape or form controls the spark advance....for some reason my research indicates that it allows vacuum advance when the car is in 4th gear. That is unless I have completely misinterpreted something and would gladly accept education in this matter.

My question is, rather than spend $32 on a new part that may possibly be detrimental to the performance of my car, should I just plug this hole with another fitting, or is there some advantage to running the correct switch in accordance with 1974 emissions standards?

As always, thanks for your input....gettin closer to puttin this puppy back on the road!

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post #2 of 3 (permalink) Old Apr 20th, 10, 9:14 PM
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Re: Muncie TCS switch question

It's a straight thread, so finding a plug may take a little checking into. I broke the center plastic plunger assembly out of mine and filled it with 1 minute permatex sealer. I was told it's not worth the trouble to hook it up. That my 2 cents.
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post #3 of 3 (permalink) Old Apr 20th, 10, 9:26 PM
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Re: Muncie TCS switch question

Yes, definately no need to hook it up. This isn't 1974, and with the poor fuel around today, you need spark advance in all gears. Just leave the switch in the side cover of the trans, it won't cause any problems to leave it. Don't worry about hooking up the relay and vacuum control solenoid either.

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