RMVette

My '70 doesn't have one, is it necessary? Looking at the assembly manual, it wires to a switch on the side of the transmission. Was it for only a manual, auto, or both? When is the solenoid energized? What would happen if you don't have one? Thanks all in advance! :seeya


[Modified by RMVette, 9:38 PM 10/16/2002]

Turbo-Jet

TCS: transmission controlled spark, an emission device that controls the operation of the distributor vacuum advance. When the engine is below 63 degF or above 232 degF, or the transmission is in 1st or 2nd gear, the solenoid will block the full vacuum signal to the distributor. The signal is not blocked for 15 seconds after starting the engine to prevent stalling. The TCS system is not required unless you are seeking originality or need to pass an emission test.

RMVette

Thanks for the answer!

vettfixr

On a 4 speed car it also only allows vacuum advance in 4th gear. What a piece of work this system is. I disconnected the whole thing and set up my spark advance. It felt like I plugged in 50 horsepower.

GaryS

The above descriptions are right on and accurate. A properly functioning TCS system won't affect your drivability at all. The inputs to the TCS system are: gear position (3rd and 4th for your car - I think), temperature of the engine, & a timer, mounted on the passenger side of the firewall. So many of them have been disconnected that if you don't have all the pieces, then you start looking at major cost. So many have just run a straight piece of vacuum tubing from the carb to the distributor.
Gary

Juliet

TCS solenoid for my '70 cost about $50. They were used in many other GM cars (like Camaro) at the time. The LT-1s got the AIR pump since it robbed less HP than the TCS. In my case only the unit on the intake was missing (and some hoses). But I haven't hooked it all back up yet. :lol: Shhh, don't tell the smog police! :jester

RMVette

ttt .... for l2vette. Hope this is what you're looking for.

l2vette

Thanks for the great info!! Out it comes!!