I've been struggling with this for a while. When I first start the car it jumps to 2000 rpm. Blip the gas pedal and it drops to 1000 rpm and goes to 1500 rpm then drops to 1000 and starts the cycle again. I have changed the temperature sensor because I was getting that code. No difference. This past weekend I changed the waterpump, timing belt, balance shaft belt, heater hoses and radiator hoses. I got intimate with that damn car. Still have the high idle and surging. The car has 140,000 miles. Original hoses and belts looked good but since I was in that far I figured what the heck. Not a job for the faint hearted. I'm thing of changing the O2 sensor next because of the mileage. Anyone got other suggestions?

 

ok my h22 did this and i changed the following and its nearly gone. execpt that i runs from like 900-1100 so not a big deal. then i hit the gas and it stops

i double checked and redid all my vaccum lines.. the ones over where my Fuel pressure regulator are. i had backwards. those were fixed i also replaced my IAV or whatever idle air valve. i hear on the f22 its on the back. its has two plugs for coolent and a motor on it. on my h22 its right up front.

 

Try this. There is a screw on the top of your throttle body, it sit vertical( like the throttle plate). With the engine running, turn that screw in a little at a time until it stops surging. If the screw bottoms out and the car is still running then you have a vacuum leak somewhere. Back the screw out a little, find and fix the leak, then if it is still surging, repeat the first two steps.( if the screw bottoms out and the car shuts off, everything is ok)