What could cause this?
Thread Starter
Junior Member
Joined: Mar 2002
Posts: 43
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From: new brunswick canada
What could cause this?
Hey there guys and gals!
Ok... here it is.
I've been having torque converter lockup problems.
I have an 86 Iroc-Z 305 tpi with a 700r4 tranny.
My tc used to lock up all the time...until one day it started acting up! Most of the time it won't lock up at all. Sometimes though I can get it to lock up on the highway if I let off the gas and press the brake peddle for at least 10 seconds. And sometimes if I hit a good bump in the road it will lock up too. I have changed the fluid and filter and adjusted the tv cable. I have even hard wired the thing under the driver side dash to try and make it bypass so that it locks up all the time. All with no results.
I am thinking that if the switch at the brake pedle was bad, It shouldn't work at all. Usualy when switches go bad...they are totaly bad. So it's almost like something is sticking. But what the h*** could it be? I have looked into how a tc works on the howstuffworks.com page and I don't see what it could be. It explained to me everything but the lockup clutch.
Now I am thinking that there is a selinoide in the tranny to controle the lockup. (just a guess) but could that be sticking maybe? Or what else could it be? What else would controle the lockup?
Any help at all would be great.
Even if your not sure...let me know what you think. Anything at all would be a help.
Thanks
Ok... here it is.
I've been having torque converter lockup problems.
I have an 86 Iroc-Z 305 tpi with a 700r4 tranny.
My tc used to lock up all the time...until one day it started acting up! Most of the time it won't lock up at all. Sometimes though I can get it to lock up on the highway if I let off the gas and press the brake peddle for at least 10 seconds. And sometimes if I hit a good bump in the road it will lock up too. I have changed the fluid and filter and adjusted the tv cable. I have even hard wired the thing under the driver side dash to try and make it bypass so that it locks up all the time. All with no results.
I am thinking that if the switch at the brake pedle was bad, It shouldn't work at all. Usualy when switches go bad...they are totaly bad. So it's almost like something is sticking. But what the h*** could it be? I have looked into how a tc works on the howstuffworks.com page and I don't see what it could be. It explained to me everything but the lockup clutch.
Now I am thinking that there is a selinoide in the tranny to controle the lockup. (just a guess) but could that be sticking maybe? Or what else could it be? What else would controle the lockup?
Any help at all would be great.
Even if your not sure...let me know what you think. Anything at all would be a help.
Thanks
Senior Member
Joined: May 2002
Posts: 510
Likes: 5
From: Santiago, CHILE
Car: 1986 Pontiac Firebird Trans Am
Engine: 305 Tuned Port Injection
Transmission: The famous 700R4
Axle/Gears: No idea
Sound like a bad connector which produces intermitent electric connection.
TCC is electronic contolated.
Connectors are in: V. Speed Sensor, ECM, attached to tranny case (with an external and other internal connection), one or two attached to control solenoid (into tranny). Some this connector are under high heat operation (note that are plastic pieces). Review it. At first, go to the conn. attached to the tranny case. Clean it with "electronic terminals cleaner" (proceeds with care. The conn. can be burned and will break it).
Regards,
Denis V.
TCC is electronic contolated.
Connectors are in: V. Speed Sensor, ECM, attached to tranny case (with an external and other internal connection), one or two attached to control solenoid (into tranny). Some this connector are under high heat operation (note that are plastic pieces). Review it. At first, go to the conn. attached to the tranny case. Clean it with "electronic terminals cleaner" (proceeds with care. The conn. can be burned and will break it).
Regards,
Denis V.
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Since touching the brake can affect it, I'd check the brake light switch. It has contacts for the brake lights (normally open) and TCC power (normally closed). When you touch the brakes, the TCC power is interupted (contacts open), and the TCC unlocks. With the brake pedal all the way up, the contacts close and the TCC can lock.
It could be a bad connection, bad switch, or mis-adjusted switch.
Of course, it could be any of the connections from there to the tranny as well. The purple wire at the tranny should have 12 VDC with the ignition on and brake pedal up.
It could be a bad connection, bad switch, or mis-adjusted switch.
Of course, it could be any of the connections from there to the tranny as well. The purple wire at the tranny should have 12 VDC with the ignition on and brake pedal up.