Transmission Controlled Spark Solenoid
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 1,132
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Transmission Controlled Spark Solenoid
What the hell is a Transmission Controlled Spark Solenoid and where is it located on a 71 corvette?!! I'm installing my engine harness right now and it has a connector that goes to it, but I can't even seem to find where it would be plugged in. Any help would be appreciated.
Thanks,
Michael
Here is the connector (blue and orange wire)
Apparently it's located near the passenger side cylinder head.. can someone point it out?
Thanks,
Michael
Here is the connector (blue and orange wire)
Apparently it's located near the passenger side cylinder head.. can someone point it out?
Last edited by majic1984; Jan 2, 2005 at 03:14 PM.
Heel & Toe
Joined: Oct 2004
Posts: 24
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What those are
First picture is the fiber optic heads to go in your light assemblies to power the indicators on the console. I think the second picture is a sensor for the position of the headlights.
Last edited by gpowellpec; Jan 2, 2005 at 03:52 PM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
The trans spark selonoid is supposed to be located on the intake mounted to a stud on the intake right in the center. It is designed to not allow vacuum advance until you are in 4th gear and the engine is up to temp. A very primative emission control device. I'll say that there is only a few left working and they are on NCRS cars. I had one on mine when I originally built the car and quickly took it off. It serves no performance at all so it is not on my car. The lower photo is a sensor that tells you if the headlights are in there full up position. There should be a light on the dash that lights up if the headlights are not in their locked position. That does work on my car.
After looking a little more at your photos your trans spark selonoid will not work. There should be a temp sensor in the head on the passenger side to tell the system that it is up to temp. This is different from your temp sensor.
After looking a little more at your photos your trans spark selonoid will not work. There should be a temp sensor in the head on the passenger side to tell the system that it is up to temp. This is different from your temp sensor.
Instructor
Joined: Dec 2002
Posts: 242
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From: Port Orchard Washington
For a 71 specific:
The connector you show connects to the TCS solenoid on the drivers side of the carb, front on a bracket that secures with the front left carb. holddown bolt. The solenoid also controls vacuum advance (allows only in high gear and reverse). You also need the reversing relay and the time delay relay for this to work. Also the temp. sender in the passenger side head and the transmission switch. The following parts needed are:
12322552-Temp. switch-$20 at GM.
3990842-Reversing relay-$25 at ebay.
3990843-Delay relay-$25 at ebay.
3961567-Trans. switch (4 speed)-$20 at GM.
8683502-Trans. switch (auto)-$20 at GM
3275602-Carb. solenoid-$35 at doc rebuild.
I have this system on mine and it works with no effect on performance or gas mileage. I recommend, though, that unless you really want originality that you skip this system. At about $150 for everything and waiting for the relays to become available on ebay it might become aggravating assembling everything and making it work. I have the original troubleshooting guide from GM for this 71 specific system and it helps quite a bit. All of the numbers come from the Assembly manual and extensive research.
Sorry so long. Hope this helps.
The connector you show connects to the TCS solenoid on the drivers side of the carb, front on a bracket that secures with the front left carb. holddown bolt. The solenoid also controls vacuum advance (allows only in high gear and reverse). You also need the reversing relay and the time delay relay for this to work. Also the temp. sender in the passenger side head and the transmission switch. The following parts needed are:
12322552-Temp. switch-$20 at GM.
3990842-Reversing relay-$25 at ebay.
3990843-Delay relay-$25 at ebay.
3961567-Trans. switch (4 speed)-$20 at GM.
8683502-Trans. switch (auto)-$20 at GM
3275602-Carb. solenoid-$35 at doc rebuild.
I have this system on mine and it works with no effect on performance or gas mileage. I recommend, though, that unless you really want originality that you skip this system. At about $150 for everything and waiting for the relays to become available on ebay it might become aggravating assembling everything and making it work. I have the original troubleshooting guide from GM for this 71 specific system and it helps quite a bit. All of the numbers come from the Assembly manual and extensive research.
Sorry so long. Hope this helps.
