I have been experincing a problem with my 91 olds cutlass supreme 3.4 for some time now. When the car gets hot and I accelerate from a stop position and then I deaccelerate, the rpm fluctuates up and down and the car stalls. However, when I accelerate slowly I have no problem. Furthermore, when release the gas pedal and I hit it slightly again and then I release it, it will not stall. I have tested it in parking position by accelerating and deaccelerating and the rpm behaves normally. Other than that, the car runs fine. I have changed the egr valve, oxygen sensor and I have cleaned the iac. I get no error messages in the computer and the engine light does not come on. The car starts fine all the time. Any assistance will be greatly appreciated. j.k