What the heck is a TCS solenoid?

[grega57]

Okay I know it's a "Transmission Controlled Spark" but for a dummy, what the heck does it do and is it needed? If so does it matter which wire goes to which post. It clicks when I reconnect the battery no matter which way I connect it. The truck is a "70 w/307, Rochester 2GV carb, manual transmission.

[john]

The TCS controls the vacuum advance. It will only work in high gear. There should also be a solenoid on the engine with the vacuum hoses going to it. There is a switch in the trans and a temp sensor to control it. Only works when engine is at operating temp. Most of them get deleted if you dont have all the parts.

[grega57]

This is a picture of it...

[kwmech]

TCS was the early version of controlling NOx, which is what an egr valve does on todays vehicles. It only allowed vacuum to the dist when engine was hot and in 3rd or high gear only. With todays gasoline and the engine you are running, I would remove it.

[grega57]

When I remove it where should the vacuum hoses go? On one side of the unit I have two hoses, one from the back/top of the carb and the other from the vac. advance. On the other end the single hose goes to the top right of the carb.

[70GMC396]

Good Question