I have a 1992 Sc 300. When the car is cold, when I step on the brake peddle, the revs jump high then go very low, as if the car is trying hard to breathe and wants to turn off..it almost feels as if the car wants to lunge forwards and starts to jerk. Has anyone ran into this problem? For what its worth, my car has all of the common problems/oil leaks, as well as no working heater or air conditions.

Thanks!

 

sounds like a vacuum leak. spray carb cleaner around the engine and see if the idle changes

 

https://www.clublexus.com/forums/per...lp-needed.html

That is my thread of a similar problem, it was the ECU causing most of the problems. Getting that fixed corrected everything but a bad knock sensor.