well im having a very annoying problem on my 88 rx7, when i start the car its just fine warming up but when it hits idle it just sits at 1000 rpms and surges to about maby at most 1200rpms and and back down to 1000. i looked for vacuum leaks but cant find any , i adjusted the TPS and still no luck. sometimes when its all warmed up and i slightly but my foot on the throttle it will stablize but it wont drop from 1000rpms. also the idle adjustment screw doesnt effect anything. it also has a very hard time cruising under 45mph, when i try to hold it at like 30mph it will flutter a bit then do a slight acceleration and it does this over and over again, can anybody help?

 

Check the throttle cable. It may be loose or too tight. I say that because I had that problem and I can't remember if it was loose or tight.

 

How did you adjust the TPS?

 

If the TPS is really adjusted correctly (TPS test light) then you've got a vacuum leak. Use propane/starter fluid to pinpoint location (search).

 

i used a volt meter to adjust the TPS to 1.0V and it still has problems. i tryed using the propane method and the carb cleaner method and nothing has come up. i even unplugged the pressure sensor tube and sprayed carb cleaner in the hole while the engine was on and nothing happened.

 

You need to make a TPS test light with a couple of 12V led's from Radio Hack, or buy one from Banzai, otherwise listen for the 1-2 clicks. Step 1 is to get the TPS adjusted right and measuring 1V with a VOM doesn't cut it.