when i start my car it jumps up to about 2000rpm then drops to 800. but when i take off and stop it idles at 1500-2000. i replaced most vac hoses. just got the car need help. new to rotary thanks

 

probably sticking ports letting in too much air and screwing up the computer - mine did the same

 

Check your TPS.

 

Could be the TPS although it would have to be really out of wack to be idling that high. After you've checked the TPS, you might want to check that the throttle isn't binding somewhere. take it for a spin and park it if the high idle - pop your hood and make sure the throttle is coming to rest as it should. If it's not snapping back all the way, lube the crap out of the linkage until it does. I had this problem and I was actually setting my TPS with the throttle out of position - this only compounded the problem

 

the throttle is not sticking. i just finished the bin rust problem. i found a big hose coming from the motor going to the cat area not hooked up and a vacume hose. what is it for. i have an exhaust leak, there is a big hole in the exhaust where it looks like that hose goes , is there supost to be some thing there. i want to get rid of the cats and go straight exaust.im used to old gm cars. what sensors can i remove with out ******* up the computer