Idle Air Control Valve?

drivingdiscodriving · 10-07-2005, 11:54 AM

My 96 GT has been running very poorly, idles low, seems to be missing, and misses very badly during acceleration. All the codes were related to EGR and O2 sensors, but both are fairly new. I had a mechanic tell me it was the IAC valve. Could this actually be the problem, or another false lead?

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Chopper · 10-07-2005, 12:33 PM

These are classic fuel and/or spark problems.Start with the cheap things.Unless they are new,replace the fuel filter,spark plugs and wires,and air filter.Look for any vacuum leaks by spraying a small stream of WD-40 around the intake manifold and any hoses connected to it.The egr could be sticking and cause all the symptoms you indicated but i'll bet new plugs and wires will go a long way toward a remedy.The newer cars will continue to run well right up to the point of complete failure of plugs and wires.Fuel pumps will usually give little or no warning before complete failure.Please repost and tell us how this turns out.

Swells 03 GT · 10-07-2005, 12:39 PM

I agree, even if you have changed the plugs and wires lately just pull at least one plug from each side of the motor and check wouldn't hurt. Don't forget the cap and rotor.

drivingdiscodriving · 10-07-2005, 03:17 PM

I'll check the plugs/wires and EGR this evening.

Gaspi101 · 10-07-2005, 04:39 PM

Quote:

ORIGINAL: drivingdiscodriving

My 96 GT has been running very poorly, idles low, seems to be missing, and misses very badly during acceleration. All the codes were related to EGR and O2 sensors, but both are fairly new. I had a mechanic tell me it was the IAC valve. Could this actually be the problem, or another false lead?

Your mechanic doesn't know what he's saying. The IAC will only be the culprit when you're idling, never when you're accelerating. IAC: Idle Air Controller. It regulates air when your throttle is closed. If you're experiencing poor acceleration, then it can only be three things: Fuel intake, Air intake, exhaust management. Given that you already have thrown up two exhaust/emissions related codes, I'd start there. Check why you're getting this O2 fault code if the sensor is new. Wires fraid? How about your EGR valve? Is the valve stuck open, or closed? None of these things by themselves will lead to poor acceleration, but put them together and they may be the problem.

Also! Check your MAS (mass airflow sensor) located on the MAF. That alone leads to exactly the problem you're describing.

Of course, the most common problem is fuel intake/ignition: spark plugs dull, plug wires fraid, most likely: fuel filter clogged, etc. Just as the boys above said. Just do some checking yourself, and do yourself a favor: don't go to that mechanic again.

andy98gt · 10-08-2005, 03:09 AM

Its prolly your fuel filter. If it was your IAC, if its off your car wont stay on unless you gas it. If its got a leak it might be bad, but usually there either all the way off or on. those dont tend to hang. Not on 4.6's atleast. Get some fuel injector cleaner to. By the way the MORON that told you check your cap and rotor is a fricken idiot. YOU HAVE COIL PACKS. NO DISTRUBUTOR !!! Learn about your car before you talk Swells or w/e your name is.