I have a 87 t2 s4 that i have been working on. I have a 3rd gen upper and lower intake, rtek 1.8, FMIC, 850 cc injectors, 3 in exhaust, ect. I got everything put back together after pulling the motor to clean up the engine bay, but now i have an idle that stays between 2000 and 2200. Ive checked for vac leaks, got the tps adjusted, throtle cable is good. I feel like i have checked everything i can think of. Does anyone on here have any ideas? I havent checked the timing yet but i dont know how well ill be able to check it with it idling so high, Any help or ideas are appreciated. I've searched and searched and have run out of ideas. Thanks in advance Zack

 

You said you checked the throttle cable, but if it's too tight, it could be holding the throttle plate open which would cause high idle. If thats not the case, then perhaps the throttle plate gap is too open. This can be adjusted. The sandard gap is quite small.

 

Have you checked the thermowax to make sure it's not sticking?

 

Does your car start up fine (enters high rev cycle then settles into a 1000rpm idle) when the engine is cold?

If so, i'm having the same problem on my 86 NA (completely stock). As the temp of the engine increases, the idle steadily increases to about 2000 rpm. I've checked the throttle plates and cables, and nothing is seized. TPS is set. However, the BAC might not be functioning (unplugged it with the engine idling and it had no effect on the idle).

Does, anyone know the proper tension on the throttle and cruise control cable, how to test the thermowax, and how to test if my BAC valve is functioning or not?

Thanks in advance.

 

does anyone know whats going on?

 

lololol try having a idle at 5-6k and then drops to 4.5k rpms lolol talk about letting it warm up before revving it up...

 

you have a FD throttle body then,right?
there is a idle screw on the Bottom of the Throttle body that is hidden from view by the Elbow.
Take the elbow off and See where it is then put it back on and adjust that screw.

 

I did find that screw and got it down to 900 now thanks for the help I have a little more fine tuning on it but im getting somewhere