Idle surge with a side of CEL

[froodawg]

Idle ramps from 1500 to 2k after stop 'n go for a few minutes, CEL indicator lit. I took the car to a local autozone for a free diagnostic - was told I needed to replace the idle speed control actuator. I know that the code that popped up gives me several possible causes, however none of them make much sense. Could be the intake, could be the throttle, could be the ICA^, I really don't know what to think. Car's been running fine and just started surging on my way home from work yesterday.

I'd recently had my harmonic balancer and a handful of belts replaced because of a rather nasty pothole (AC, alternator, etc.), and prior to that I'd had no problems with this vehicle.

My question is this, what is the most likely culprit given my mods and the timing of this problem as I've described it? My car is quite important to me of course, but I'm not in a position to dump a lot of money on diagnostics or replacements right now.

 

[timot]

so it is idle surging all the time now, or just when you come to a stop after you have been driving a while?

 

[1gDSM4g63]

First check if there leak, then clean out your throttle and if it is still surging adjust the BISS; http://vfaq.com/mods/BISS-1G.html.

And then, if that doesn't solve the surging test the isc with a multimeter and if need be changing the ISC is the last resort.

 

[froodawg]

so it is idle surging all the time now, or just when you come to a stop after you have been driving a while?

From a cold start, it tends to run fine. Once the engine is warmed a little, it will begin to surge as I posted above.