I have a 1994 Celica GT and I recently had this problem. My RPMs will go really high while in neutral (or with clutch in while shifting) and I have to pull my gas pedal up with my foot. The first time this happened, which was a few days ago, I fixed it by just lifting up the gas pedal but now it stays at high RPMs. I am wondering if anyone else has had this problem or has any idea what it could be. I've already checked my throttle cable and it is not to tight, and I have cleaned my throttle body just in case it was sticking. Please, if anyone has any ideas as to why this is happening, comment.

I had a similar problem, i replaced the throttle pedal assembly and it went away

Throttle cable is probably sticky. Or the throttle pedal needs a little lube.

Have someone get in the car and pump the pedal with the car off while you check out the cable and throttle body, has to be something catching or a spring binding.

Same problem right here I did a temp fix buy a throttle spring at advance auto parts orielys or autozone and use 2 zip ties to put it on place on the throttle adjust and enjoy and you need to replace the whole throttle by the way.