Torque Convertor Not Locking Up

On my way to work today I noticed that the torque convertor was not locking up. I could tell because the RPM was higher than normal and the rpm's fluctuated a great deal with very little difference in gas pedal pressure. The amount of tranny fluid is good.

ANy ideas on what it could be or what to check for? Thanks.

-Mike

I would first check the TPS, then check the solenoids (I believe it is either #2 or #3) that controls lock up, and last I would check the TCU. The TPS is the culprit the majority of the time as it feeds info to the TCU. I believe, and do a search on this, that you can disconnect teh TCU and it will default to a locked up torque convertor. Of course, you will have to shift through the gears. I had the same problem a year ago and it was the TPS.
Good Luck
BSD

How can I check the TPS? It's on a 96 so it is not adjustable. There is no check engine light on.

-Mike

also check the switch mounted on the brake pedal... it may be stuck - so that the TCU 'thinks' it sees braking input and keeps the convertor unlocked.

Mine messed up on my 89 trail rig (I had a bad o-ring on the speedo quill shaft that let a bunch of ATF pump out of the t-case, up the cable, and all over the stuff under the dash) so I just converted it and the shifting over to manual controls (two switches on the console - one for TC lock/unlock and the other for manual 1-2 or 3-4 shifting)

Thanks Woody. It looks like it was the brake switch. It seems when I was doing some under-dash wiring I popped the brake switch back off the brake pedal. Not enough to affect the brake lights but enough to affect lock-up of the TC. I pushed the switch down as far as it would go on the pedal and it seems fine. I will just have to see how it goes over the next day or 2. :cheers:

-Mike