Chosen Won

Hello guys, long time no post. I am having a bit of trouble with my 90 vert. I can't get the search function to work, so I am just posting the question.
My car will not idle after it warms up. It idles for a second, then it starts surging, then it eventually surges so hard it stalls. Also, when I depress the clutch, the car is starting to stall more and more.

Usually, I can turn on the climate control and the car will at least stay running, but now it seems that this won't even work. What the heck is wrong with my car?

bogus

sounds a lot like a bad IAC - Idle Air Control.

It's on the lower right side of the throttle body and it controls idle. If it ain't holding idle, this is a good place to start looking.

I would suggest removing the air intake tube and spraying a lot of carb cleaner into the throttle body, and especially into the little "V" between the barrels. That might just clean it up.

Chosen Won

I assume I should do this without the motor running? J.k. I will try that this evening. Should I reset it? And if so, how?

Z51L9889

It sounds to me like the Idle Air Control motor is either stuck or not working. I suggest removing the IAC and the IAC/manifold coolant housing from the bottom of the throttle body so you can clean out the built up carbon. This housing is a split casting that has a coolant passage on one side and the idle air passage on the other. It's not uncommon for the gasket to degrade over time and allow a little bit of coolant into the idle air passage. This softens up any built up carbon deposits and basically turns them into glue which can cause the IAC motor to stick.

I had exactly the same problem that you are describing and this was the cure.

Chosen Won

Is there any way that you could tell me what I need to do? Also, what do I need to do to recalibrate and or reset the IAC after it is taken apart and cleaned?