Hey, everyone. I have an '87 N/A. I tried searching to see if anyone else was having, or had, the same problem as me. My motor seems to idle wherever it wants to while it's running. Sometimes it'll idle at 2500, sometimes at 1000, sometimes 1500, 1800, you get the idea. It changes pretty much between stop lights. Anyone have any ideas as to what's going on?

 

It may be your TPS. My 87 NA does this at times, but sometimes the idle bounces. It will go to almost 0 shoot to 1000, go to 0 shoot to 1500. I am thinking the TPS may be at fault. I plan to look into this weekend.

 

i have my tps set right and my idle does the same thing, i set it where i want it and its rock solid then i hit the gas and it idles in a different spot. very aggrivating, i even have my bac unhooked so the ecu cant adjust the idle, im confused now

 

hmm... so check the TPS? any other suggestions?

 

well the tps is always the first thing you should check for idle problems. check that and then see what it does, when you try to adjust it make sure you are connecting the initial set coupler or the bac will just try to make up for the adjustment

 

Hook up a digital voltmeter to the TPS pins at the ECU and leave it for at least a week. Check the volt readings throughout your whole range of driving, but particularly the voltage settings at idle. Adjust the tps setting several times throughout the week and you will get closer and closer to the correct TPS setting for your car. If this doesn't solve the problem then its not the TPS, but I would eliminate the TPS as the culprit first. After that you might want to look at throttle plate settings in the TB and the fast idle cam setting at the thermowax.