High Revving

I have a '95 Mazda Protege with 90K miles. Last year, the automatic transmission blew up. $1800 later, it was rebuilt. They gave me a year warrantee. I’ve already had it back once. Now, still under warrantee, it has trouble going into 4th until I have been going >60 for 3-5 minutes. I am taking it back because that is clearly transmission-related (I think). My problem is the flip side: After being in stop and go traffic in rush hour, the car’s RPM will climb into the 3K-3.2K range when stopped. I have to stand on the brake to keep from moving into the car ahead of me when we are at a stop. The next time I get into the car, it has somehow reset such that the idle is back to normal. Is this a transmission-related problem that I should expect them to fix when I bring it in for the top end problem? What else could it be and is it expensive? (No lights or indicators are on and everything else seems normal).

Most likely your high-revving problem is a sticking IAC (Idle Air Controller). This may be due to deposits on the plunger causing it to stick open. A thorough throttle body cleaning would be my first attempt, and it is in-expensive. A gasket or two and a can of sensor-safe throttle body cleaner.

Check the wiring harness on the transmission. Also report that shop to the BBB for the sorry job and get an attorney to recoup your losses.

You could have a faulty TPS (Throttle Position Sensor) If its reading high (Telling the computer the accelerator pedal is floored or close to floored) the computer will definately delay the shift. A scanner to monitor the TPS readings is what you need now. Dont go hollering at the tranny guys yet, the TPS is on the engine at the throttle body.

I had a newer model Buick in my brothers body shop recently he called me to check the transmission on, it wasnt going into overdrive and the RPM’s were running high. After scanning and scoping it with my MODIS, I saw the TPS maxing out at 4.84v at idle with the gear selector in “P” Guy was prepared to pay for a trans overhaul but ended up paying $85 for TPS plus my time.