Mechanics

AUTO TRANS SHIFTS ONLY WHEN GAS PEDAL RELEASED

Toyota Corolla

1991 Toyota Corolla DX Wagon 294K
While driving I have to release the gas pedal completely and wait a second for the automatic transmission to shift up as normal. I do this for each gear. I had this problem briefly a long time ago(like 20,000 miles ago) and it went away and now it's back for good. Reverse works fine. Auto downshift works fine. Auto lock up solenoid engages and disengages fine. It happened on the same day I changed my spark plug wires and rotor. I put the old parts back on but the problem persisted. Does it matter that the car is blue?
I read in the forum it could be a faulty shift solenoid in the transmission. I do understand it is kind of time to rebuild the transmission anyway. But what is causing my shifting problem? One guy said kickdown cable, one guy said internal problems rebuild the whole thing. Thanks.
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Sweep2win
June 23, 2006.



My AT fluid is at a normal level with no leaks. Fluid and filter were changed about 10,000 miles ago too. Doesn't anyone have a clue what the problem is?

Tiny
Sweep2win
Jun 25, 2006.
Try checking the TPS and the VSS before you get to the solenoids in the tranny. TPS is the throtttle pressure, and VSS is the governor pressure also the ECT for lock -up.

Rasmataz
Jun 25, 2006.
Thanks I'll try the TPS today. My VSS should be fine because my speedo still works. ECT is that part of my ECM or is that something sitting on my AT?

Tiny
Sweep2win
Jun 26, 2006.
ECT/CTS

Engine Coolant Temp. Or Coolant temp. Sensor it has to do with Lock-up

Rasmataz
Jun 26, 2006.
I jerked around with the TPS and the AT went back to normal. I'll still change it but it has some calibration points on it. I didn't note the original position before I took it off. I put it back on and the car runs fine. Should I still try to calibrate it? How is it done?

Tiny
Sweep2win
Jun 26, 2006.
Turn key On

Find the check connector terminal ECT stick your multimeter positive probe on it and the other to good ground or to E-1 the voltage will raise from 0 to 8 volts as you gradually step on the gas pedal in a linear way. When you step on the brake it should drop to 0 at wide open throtttle

Adjustment make sure its on 0 voltage when you probe it-if it is you're good to go other than 0 reading adjust the TPS to read 0

Anyway if its shifting right your okay-if problem comes back than you know where its coming from.

Good Luck!

Rasmataz
Jun 27, 2006.