[MMunger]

I had a starter that was having issues when hot, so I ordered a mini-high torque to put in and then was going to send out my OEM one to be rebuilt.

In doing so the new mini-high torque was a 2-wire vs the stock 3 wire. Since I bought the car done I hadn't checked to see if it still had points or been swapped to a Pertronix. If it had, no need for the resistor wire. I pulled the distributor cap and sure enough it had been changed to Pertronix, easy starter swap just needing the battery and and the start wire.

While pulling the cap off I noticed vacuum module that had a vacuum inputs on both ends and an electrical connection. The electrical is connected but both vacuum terminals are not. What is this module for and where should it be connected?





If it for the carb, while I had everything off the top I got a pic of the numbers, its a 7040273. Looking this up it looks like its for a 1970 455 RA Manual, so is this for a GTO?

[Ramairnacho]

It will help us to know what car you own.

[Kenth]

The "vacuum module" is the solenoid for the T.C.S. (Transmission Control System).

[MMunger]

Originally Posted by Ramairnacho

It will help us to know what car you own.

1970 T/A, 4sp, A/C, Norwood

[jhein]

Post a few more pics of that carb. The experts may be able to tell if it's real. If it is real, it is the correct carb for that car and highly sought after.

[Ramairnacho]

Thanks for diagram I thought it was connected to transmission vacume too on a pq turbo 400 but I'm wrong. I better buy that supplement

[Formulabruce]

The TCS >>> LIMITS<< Full advance in most driving conditions. You can make it all look good, but I would never use it.

[Ramairnacho]

Formula Bruce what s the purpose of it? If full advance is limited them with modern gas will it cause more pinging. Can you explain to use why they put this gadget on our cars? I want to learn.

[Formulabruce]

Ok, Less advance is typically LESS chance to PING. Higher octane acts as a timing Retarder, it slows down the speed of the combustion.
Back to the TCS.
When designed, it ONLY allowed FULL advance when 3 things were met.
1. Engine at operating temp.
2. Car in high gear
3. Enough Vacuum to pull the advance was available at that rpm..
This would allow some passing power, but its main function was to limit Hydrocarbons ( Co ) and promote better fuel " burn" efficiency ( Not economy )
Since this came out gasoline has gone through some changes.
1. Removal of Lead ( this was a big polluter)
2. Addition of cleaners
3. Addition of MTBE ( a byproduct of gasoline that is harmless when burned, but will not dissolve if spilled)
4. Removal of MTBE and addition of more detergents
5. Addition of 10% corn alcohol ( which is what most of us have today)
The GMO corn alcohol adds more octane ( slows the burn) but it has no real density, so it lacks in compression power unless you modify the stock engine.
With the Alcohol, the TCS isnt really needed as engines are less likely to ping with the octane. The alcohol and the cleaners make the fuel much better for the environment
than it was in 1970. The TCS will reduce engine performance getting up to highway speeds for very little gain in anything with current fuel.
Current "driver" Pontiacs IMHO should be built to No higher than 9:1 and with the 421 Mod done. This way you have a large room to adjust timing, keep engine temps down, and be able to run an efficient AND Chilly AC system set to cycle, and No ping.
Transmission based Spark control ( TCS) is controlled by an TCU or ECU these days on new cars.
In California you dont need any emissions till the 1975 Model I believe, and by then the engines were choking on Exhaust gas recirculation... cough...

[mysticmissle]

I have a complete TCS system from a 70 auto, if anyone needs it to complete their cars

[SD455DJ]

We always by-pass the TCS and/or put a large BB in the vacuum hoses and add another vacuum hose for manifold or ported vacuum depending on the engine/car particulars.

Dennis