West Coast GTA Man

Hey Guys -- I did the test that someone on here told me to do (Five7Kid) to test my TCC. I was doing roughly 70 mph, kept my foot on the gas, and put my foot on the brake lightly and RPMs did not go up. I tried this a few times -- hitting the brake harder, trying different speeds, etc. But no change in the RPMs. So I am thinking that my TCC is not working properly. I know this will effect my gas mileage. What other disadvantages will this have? Am I losing any power by it not working? Is there anything other than gas mileage that I should worry about with this not working properly. How should I fix it?? Thanks for all your help!

Later
Mike

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Check out My Car Pics http://albums.photo.epson.com/j/Albu...667&a=13599419

Gran Turismo Americano "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber) & AC Delco Rapid Fire Plugs

Jason Welch

Unless you plan on going on a good long trip it would not be a problem on my list and dont believe it would hurt performance at all. The ones i had I liked better unhooked city driving because they lock and unlock at about 45 for me. Didnt like the up shift downshift upshift downshift feeling. Just a thought from a rookie though.

P.S. On your other post i've heard rumors of headers increasing gas mileage and perf.

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92 Firebird
305 tbi 5spd
straight pipes

West Coast GTA Man

Hey Jason, I would like to put headers on, but I think it would be a nightmare for me to do on this car. Maybe it won't be too bad after I remove the smog pump & stuff. How did you unhook your TCC on your other cars? How do I diagnose it? I would like to have it the way it is supposed to be. Especially if I ever want to do a road trip. Is your TCC hooked up on your car now?
Later man
Mike

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Check out My Car Pics http://albums.photo.epson.com/j/Albu...667&a=13599419

Gran Turismo Americano "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber) & AC Delco Rapid Fire Plugs

Jason Welch

unhooking it worked i never even had them throw a code either. give me a ride all it feels like is another gear. From what ive seen you can get smog friendly headers and y-pipe. Last price check i had was $289 for the set.

P.S. I have a 5 speed. no probs i love it

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92 Firebird
305 tbi 5spd
straight pipes

West Coast GTA Man

Eventually I will get Headers. But I will eliminate all the smog crap first. I know the TCC is causing my mileage to be a little worse. When I drive now, it it seems almost like it is "Lower geared" it seems to be more laboring, like more RPM's. It is hard to explain it. I just want to figure out how to get it back to the way it should be. I know that my car had some tranny work done before I got it, because it is missing that plastic cover that covers the flywheel, and the tranny looks real clean. Maybe this has something to do with it.
I will figure it out some how.
Later man
Mike

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Check out My Car Pics http://albums.photo.epson.com/j/Albu...667&a=13599419

Gran Turismo Americano "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber) & AC Delco Rapid Fire Plugs

Ed Maher

The TCC is very important in a 700r4 especially with stock-ish tall gears. When you are driving down the highway your RPMs are gonna be near the stall point of the converter, which is where the converter is least efficient. Inefficiency=heat=worst enemy of an auto trans.
There are 2 things that could be going on. Your TCC might never be locking, thus you don't feel it unlock when you tap the brakes. OR, your brake switch could be bad, and not cutting power to the TCC when you hit the brakes. So, you have to determin if it is locking or not. This is easy. During highway driving, steady state, just squeeze the throttle a little harder. Do the rpms flare up as you accelerate, or do the RPMs simply linearly increase w/ speed. The latter means it is locked, the former means unlocked.
If it is locking and just isn't unlocking w/ the brake switch this isn't a really bigg deal. Thats the way mine is, and i really don't care enough to fix it.
If it isn't locking at all, you need to figure out why. First get under the car, and with the key 'on' you'll need to check the voltage at the connector for the tranny. It's a 4 terminal plug going in from the top on the driver's side of the tranny, near the lip of the tranny pan. I'm not sure which one is which, consult a diagram, but one wire is a switched ground (TCC enable/ALDL F), one is the TCC hot, and the other is hooked to the 4th gear/overheat switch in the ECM as a pull down signal. TCC hot should be 12 volts. If not, either your wiring harness or brake switch is bad (suppose it could be a fuse as well, but i'm sure you would notice other stuff not working as well if that was the case.) If you have hot, then your next step is to drive it and hook up a paperclip between termninals A and F in teh ALDL (reference my TCC lockup tech article if you need help with this) As soon as it shifts to 2nd the TCC should lock and bog you down pretty good. If not, then your TCC solenoid is bad. Replacing it is easy, once you drop the pan you can trace the wires and at one end (sorry i forget) you'll see 2 wires going to a coil looking thing w/ 2 bolts holding it in. Take those out and simply pull it out.

Besides just keeping your tranny alive the TCC will also give you at least 2-3mpg better gas mileage on the highway, so it is very much in your best interest to figure this problem out.
...ed

Grim Reaper

It sounds to me that your TCC is also locked. If you are travelling at 60 mph, your rpms should be around 1,800-1,900 rpms if you have 3.23s and your TCC is locked. If the rpms are NOTICEABLY higher, then your TCC is not locked. It is more than a couple of hundred RPMS btw.

When your TCC is unlocked, no tranny fluid goes through the cooler. Driving for prolonged periods without a locking TCC will cause the tranny to overheat and shorten its life.

Also, the TCC is controlled inside the eprom. If you have an aftermarket eprom, the "unlock prevention speed" may have been altered in your car.

Ed Maher

Glenn, that is a question i have always had. The only person i have *ever* heard promote the theory that the cooler doesn't function unless the TCC is locked is bruce. Now i know he's looked at a lot of things in his time, but honestly that seems like the stupidest thing GM could do in designing a tranny considering the amount of time a tranny spends with the TCC unlocked. Consider the simple case of pulling off the highway to get gas. You think GM would design it such that in this situation you are effectively cooking the tranny by allowing it to bathe in it's own heat until you get back on the road. GM does dumb stuff, but i don't think they are that dumb.
The simplest test i can think of for this is to unhook the cooler lines at the radiator and turn the engine on...if you pump tranny fluid all over the ground then his theory is obviously wrong. Considering i have heard more than one story where this has happened (broke or disconnected tranny line blowing fluid everywhere) I'm inclined to believe that it is simply not true and the tranny does always pump fluid through the cooler. I'm not about to start tracing fluid diagrams of the 700, but like i said, a simple common sense apporoach to the answer leads me to my belief.
I can also explain where this myth prolly started. As i stated in my above post, cruising dowm the road at the stall point of the converter w/ it unlocked is it's most inefficient operating point, which will quickly burn up the fluid. Thus, old eggheads who were 'improving' their driveability by unplugging the TCC also tended to burn their trannies up. The quick solution for someone not thinking of the dynamics of a TC would be that the cooler must not be functioning, when in fact you are simply overwhelming it's capacity by basically generating as much slip as possible in the TC.
note, i could be completely wrong, bt i doubt it since i know for a fact that tranny fluid will blow out if you disconnect the lines.
...ed

West Coast GTA Man

Hey guys, thanks for the help! I am going to check it out. I have 3.27 gears, not 3.23's, But I will see what the RPM's are at at 60 MPH. I am going to try what you saaid to do on the highway ED, and see if the RPM's flare up or just go up a little. Hey Ed, I would like to see that tech article you wrote on the TCC. Where can I find it at. Thanks to all of you for your help!(Jason Welch, Ed Maher, 91L98GTA) I really appreciate it.
Later
Mike

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Check out My Car Pics http://albums.photo.epson.com/j/Albu...667&a=13599419

Gran Turismo Americano "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber) & AC Delco Rapid Fire Plugs

Ed Maher

it's with the rest of the tech articles linked off the main page of this site, lol

West Coast GTA Man

Hey Ed -- thanks man, I will check out the article. When I was cruising today, at 60 mph, my RPM's were at 1800. Maybe I am ok?¿ I will check it out though.

Thanks again!
Later
Mike

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Check out My Car Pics http://albums.photo.epson.com/j/Albu...667&a=13599419

Gran Turismo Americano "The Ultimate Firebird"
Smokin 1989 GTA- Bone stock except for exhaust. (no catalytic-stainless pipe into Flowmaster 2 chamber) & AC Delco Rapid Fire Plugs