Need Help With My Supra

[suprafast21]

Today my car is acting up. My car revs funny on neutral, when i rev it slowly it bounces up and down, right when it hits 2000 rpms, it goes back down to 1000 rpms,and im holding the gas pedal steady. and it keeps repeating itself, 1000rpms,2000rpms,1000rpms,2000rpms.it jus keeps going up and down by itself... then i gave it a road test when it gets to 2000 rpms, it like stops for like a split second, or hesitates and then goes over 2000 rpms. IM very confused, and my car performance sucks!

i checked for an vacuum leak, but no luck . this all happened when i changed my front brakes. Any one knows whats wrong with my supra?

thanks for the help!

[MyV6Flys]

In most cases that is caused by a vacuum leak. The computer is trying to set the air/fuel mixture. But because of a air leak it can't get it right. So it keeps hunting for the correct setting.

I can't figure what you might have hit doing a brake job, unless you bumped a hose up by the Mater Cylinder filling fluid if you had to.

Look for a loose hose or not on tight. The leak is Most likely after the butterfly in the throttle body, because the Idle air control valve takes care of air/fuel mixture before the butterfly.

I use a Doctor stephoscope to look for them. But even a chuck of garden hose cut to a usful size can help find leaks. Just put one end to your ear and move the other end over the motor area, listening for a suck or whistle sound.

[suprafast21]

man its a pain to find out where its leaking, but thanks for the tip, imma try that hose thingi!