TCS switch
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
TCS switch
...What does it do? The "Transmission Control Spark switch has been disconnected as long as I can remember. I finally figured out what that green wire goes to. Anybody?
pb
pb
Race Director
Joined: Jul 2001
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Generically, it locks out vacuum spark advance under certain conditions. When and how changes dramatically depending on what year, engine and transmission you have. The archives are full of discussion on this.
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
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From: Raymond NH
I'll check archives.
pb
PS
Just checked it. PFM????
I guess I ain't gonna worry about it.
Last edited by paulebrown; Mar 5, 2011 at 02:24 PM.
Team Owner
Joined: Jan 2006
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From: Crossville TN
TCS is an emissions item only. With it active, the timing is retarded at idle (vacuum is blocked so that vacuum advance can on the dist is not operational until throttle is depressed). It only serves to run your engine hotter at low speeds (which burns more hydrocarbons...but does no good for your engine). If you want the car to "look" factory correct, leave the equipment on the car but fix it so that it is non-functional. Otherwise, put that stuff in a bag and store it somewhere.
Le Mans Master
Joined: Mar 2001
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From: Ann Arbor Michigan
Safety Car
Joined: Jun 2004
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From: Lakeland Florida
My TCS unit was installed on my 73, but not connected to anything. I found out what it was for, and did not bother to hook it up. I did remove it and keep it in a bag for future use. I checked online and they are pretty expensive units to replace. Around $85 - $100 with online vendors.
kdf
kdf
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Just curious.
On my 74 350 auto the "Emissions Sticker" says CCS-EGR
The 74 Service Manual has no information on CCS but there is information on "Transmission Controlled Spark System" so my question is are these both the same with the exception of the vacuum advance solenoid being a separate unit and attached to the coil rather than the combination unit of idle stop solenoid and vacuum advance as shown on the NCRS 71 info?
The 74 Service Manual has no information on CCS but there is information on "Transmission Controlled Spark System" so my question is are these both the same with the exception of the vacuum advance solenoid being a separate unit and attached to the coil rather than the combination unit of idle stop solenoid and vacuum advance as shown on the NCRS 71 info?
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Melting Slicks
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From: Canberra Australia
2025 C3 of the Year Finalist - Modified
Here is an earlier discussion around the 1971 CEC/TCS system.
Keep in mind 71 was unique but many of the basics are similar.
http://forums.corvetteforum.com/c3-t...id-wiring.html
Keep in mind 71 was unique but many of the basics are similar.
http://forums.corvetteforum.com/c3-t...id-wiring.html
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
I bought this car new in 72 and one of the first things I did was have someone remove the "polution control" stuff. And that was part of it. After 39 years the memory dims somewhat about all the things one does to one automobile.
pb
