Ok so I have a 92 SC400 and on friday I went to work and my car was doing just fine. But when I left my car started not wanting to down shift at wot, or even half throttle. And It wont go above 3000 rpm or so.

I replaced the TPS because I know that can effect the auto tranny. I have searched for vacuum lines that may have come off, adjusted my kick down cable, disconnected my battery over night just to reset everything, double checked all fluids were full, checked all fuses, even pulled the TRAC fuse just to make sure there wasn't something go on with that causing it.

I can't figure it out. It is very weird how it was fine when I got to work and then not by the time I left.

And Help would be much appreciated.

 

Maybe shift solenoids? If i remember correctly, there are 2 shift solenoids hidden under the transmission oil pan. You have to drop the pan and drain the fluid to get to them so i'd definitely check for other possible sources for the issue before doing that. Could also be electronic, solder joins on the ecu? This is all guesswork but it sounds to me like something is telling your trans to stay in gear when it shouldnt. Does it start from 1st gear when you start the car? if it shifts up to 4th and then doesnt go back down it could be a solenoid issue, if it shifts up and down when you slow down/come to a stop but doesnt shift down when you go WOT then it could be the ECU. If the ECU isnt registering that youre at WOT it wont tell the trans to downshift

 

I shift up and down normally just fine. Except for the fact it wont go over 3k.

Only when I hit WOT it won't downshift to get the rpm up to accelerate faster.

 

Have you tried putting it in park or neutral and trying to get the engine to rev up? If the engine is still staying under the 3k range when you do that then the issue isnt the transmission but something to do with throttle. Loose cable maybe?