TCC and related issues

Victim: 1992 Pontias Grand Am

Symptoms: Runs and idles well until it is driven on a warm day. After driving at speeds in excess of 50 MPH and attempting to brake to a stop, the engine chugs and dies. It feels like a standard tranny not having the clutch depressed when coming to a stop. Engine restarts immediately in Park but dies just as fast when shifted into any gear. After attempting to restart and drive like this a few times, the ignition switch refuses to turn over the starter. After letting the car sit for a few hours, it starts and runs well.

Initial thoughts: Stalling appears to be TCC related. The car had been parked for about a year. Before it was parked, it had the second part of the problem on hot days. It would start and run fine until the engine was turned off. Then it would not engage the starter until it sat for a few hours. The engine runs well, no misses, smooth idle, good mileage, good power. When the starter does engage, the car starts quickly and easily.

Question: What could prevent the starter from engaging after driving on a warm day and allow it to work normally after sitting a while?

welcome to the forum, Jeff. I would say that this actually sounds more like a bad crank position sensor. But if you want to try to eliminate the TCC culprit, you could try unplugging the lockup/stall connector. If you look under your bellhousing, t is ontop of your bellhousing and I believe it has 4 prongs going into the bellhousing. If that doesn't solve it, then my guess would be CPS related. A lot of guys on here will have some great ideas - they should post up soon.

I will try to unplug the TCC on my day off tomorrow. My question is will the CPS cause the starter NOT to engage? I would almost suspect the ignition switch itself but I can think of no reason why it would stop functioning and then resume perfectly several hours later. Temperature seems to be a factor since it only appears to do this on warmer days. When it acts up, everything else appears to work normally, fans, lights, etc. The starter will not engage or turn over and there is not even a click from the solenoid or other relays heard. After several hours it acts perfectly normal and may continue to do so for days or weeks.

The CPS and the starter are not connected. The problem is probably related to the ignition switch like you state. It probably does not make proper contact and therefore does not make enough contact to allow it to engage the solenoid. I would however, try a remote start switch on the starter. You can buy one for a few dollars from Autozone. If the switch is bad it should turn over immediately if not you may need to check the wiring at the starter or replace the solenoid.

It may the starter solenoid, a neighbor of mine had a similar issue on his Subaru, when the engine got hot the the starter would not engage, at one point we tapped on the starter housing with a hammer and then it would engage and start right up. I don't know if this will be of any help, I'm just throwing my 2 cents in the ring.

Good luck.

Just found out that the solenoid heat shield is missing so I think that will be the source of my "won't engage starter" problem. I plan to replace the solenoid and heat shield tomorrow.

Hey Jeff....I am having the same problem myself....only thing is....I have no idea what the heck the TCC looks like and where to find it.....I have been told to look on the bellhousing.....guess what....no idea what a bell housing looks like. Does anyone have a pic of what I should be looking for, or a diagram of where to find it. Driving me nuts....or atleast until I stall.....

After reading a few tech sites concerning GM transmissions using the Torque Converter Clutch, I am getting a little leary about permanently disconnecting the TCC solenoid. Many people have stated that unplugging it will cause no harm but many of the tech sites disagree. I read that the transmission is designed NOT to have to rely on hydraulic coupling in the torque converter while cruising at hiway speeds and wasn't built to sustain it. They said that unplugging the TCC solenoid should ONLY be used as a short duration fix, long enough to get it home and get it fixed....... and that running without letting the torque converter lock up in high gear would eventually burn out the high gear and damage the front pump in the transmission. Basically, the high gear was made specifically to run with a locked converter and was not sturdy enough to handle the slippage that an unlocked torque converter would allow. Also that the front pump in the transmission was not built to supply the pressure necessary for continued driving in high gear with an unlocked torque converter. It also stated that running at hiway speeds with an unlocked torque converter would generate considerably more heat in the transmission than running with the torque converter clutch locked.
Most sites stated that the solenoid was only about $40 from GM and doing it yourself was a big PITA and a garage would charge around $250 for the repair.

I was wondering if flushing the tranny and putting in a new filter and fresh fluid might help out since the TCC in my car doesn't stay locked every time I have driven at speed. Also.... in the sites it mentioned you could connect a test light from terminal F in the diagnostic connector to ground and it would light every time the solenoid engaged. Rigging this up temporarily while driving would allow you to see if hitting the brake pedal released the solenoid like it was supposed to.

Well in the aspect of why it is dyin when you put it in gear...my bro has an 88 cougar and he is having that problem and I think I have narrowed it down to the fuel pump...you might have that checked at a shop or somethin bc thats a big deal if the fuel pump goes lol

-K.C.