After removing the IAC, is it safe to clean the IAC port with PB Blaster? Or is something else recommended. Brake Cleaner? Something else? I'm sure WD-40 isn't acceptable due to the silicone content and the Oh-2 sensor.

Is it safe to clean the port with the IAC installed and the engine running?

[This message has been edited by fierofool (edited 12-12-2012).]

Anyone know?

Try throttle body cleaner. Works great on the black goo.

Can it be used with the IAC in place or does the IAC need to be removed if I want to spray it into the IAC port? I don't want to damage the IAC.

Carefully unscrew the IAC and clean the spring, shaft and pintel end. With the IAC removed it should be easy to clean the port in the throttle body. Be careful with the spring so as not to damage it .

Do a search, there should be pictures of the process. BTW, it will take the computer a few minutes to catch up on your first drive over 35 mph.

[This message has been edited by Kevin87FieroGT (edited 12-13-2012).]

I use Throttle Body cleaner, and I do it with the IAC in place. short tiny spurts into the IAC hole.
I have considered using SeaFoam thru the IAC port to clean as well.

I've swapped out IAC's before and sprayed out the passages, but in this case I have a club member with a very high idle that I think may be the IAC. I wanted to clean out the passages before trying to swap out the IAC on the engine. I don't have the proper socket.

Thanks all for the replies. Gonna try the throttle body cleaner. If it doesn't work then I'll just install one of the spares I have.

Don't loose the thin gasket that is on the threaded part of the IAC. Might stay on the IAC on in the hole. Just keep an eye out for it.

Also clean the contacts on the IAC electric plug with the throttle body cleaner.

quote Originally posted by Dodgerunner: Don't loose the thin gasket that is on the threaded part of the IAC. Might stay on the IAC on in the hole. Just keep an eye out for it.

Preparing to replace the IAC if needed, I removed one from a spare intake and the gasket broke. Can I possibly use an O-ring as a substitute?

I did this last week. Removed the IAC, cleaned it with throttle body cleaner and a Q-tip. Sprayed a little into the passage and cleaned with a Q-tip until Q-tip came out clean. installed the IAC and drove the car a few miles. Idle no longer hunts and does not stall when put into gear (automatic) It corrected all the small problems with idle. Looked like the original IAC that is 25 years old and 100,000 miles. Hope this helps.

I've got my dental mirror for inspecting underneath the intake for broken or disconnected lines. This thing's idling at between 2500 and 3000 rpm, so if it's a vacuum leak, it isn't a small one. That's why I suspect a defective or stuck IAC. Just getting prepared in case it is. If covering the IAC port doesn't bring the idle down or make it stall, then I'll go looking for leaks. I have several TPS's, MAP's and IAT's on hand also. And shrink tubing to repair any vacuum line leaks.

CES light is on, so I'll have to pull codes to see if it's just an over set point code or something else. We'll see when he gets here, tomorrow. I've heard that no one stocks the gasket and it has to be ordered. I'll check NAPA. Thanks.

Fierofool,

Just get a can of starting fluid, spray a short spurt at each vacuum line connection. You can spray some under the plenum through the openings in the plenum. BE CAREFUL with this stuff and don't breathe a lot of the fumes. Idle will jump up when you hit the right spot. Not the preferred but quick and easy. Get new casket for the EGR and remove it, you can then clean it. Also try pushing up on the EGR valve by using your finger from under the valve, if that makes no difference is is stuck open. I went through this stuff on mine and ended up replacing vacuum lines with Dickmans SS lines and replaced EGR valve. Hope this helps some. Is there a Fiero knowledgeable shop in the Atlanta area? I am willing to help any one in my area with their Fiero problems (South West Georgia).

[This message has been edited by oldbikeracer (edited 12-15-2012).]

I'm pretty familiar with most of the Fiero. I usually use a propane torch turned on very low and pass the tip around the intake and vacuum lines. I've got better control of that than starting fluid.

With the apparent collapse of Whodeanie's shop, there are no other Fiero shops around Atlanta. Aerodonamic, ADFieros, Lee Arnette have all retired, so now it's mostly up to the owners to maintain their cars with the help and advise of other Georgia Fiero and Pennocks members.

I strongly suspect the IAC because of the very high idle, but I do have EGR valves and solenoids if needed. I'll check the EGR valve. Thanks.

Aerodonamic advised that the filter on the brake vacuum line inside the engine compartment could be the culprit, but the vehicle has very good brakes.

Good luck with it. Starting fluid is the most fun to use because you know you have an explosive situation in you hand LOL. You might also look at the large black tube that runs from the intake to the bottom of the throttle body. To bad that live 200 miles away, perhaps I will come up there for a club meeting some time. Here is a picture of my Fiero Let us know what you find.

[This message has been edited by oldbikeracer (edited 12-15-2012).]

Just got finished and he headed home. The idle was up at 3000 or better after driving 40 miles. Trouble code 21 said TPS. So, I started removing the TPS and both screw heads broke off flush with the TPS. It was still solidly anchored to the throttle body, so I took out the IAC and put a known good one in. The old IAC pintle was all sooted and had no marks in the soot to indicate that it was making any contact with its seat. Took it for a drive and still no change.

So, we started working on the TPS and got it off. PB blasted, froze, tapped on them, grabbed the vice grips to try to remove the remaining screw portions and they snap off flush with the throttle body.

Next, I go get one of my spare intakes that I took the replacement IAC from and remove the complete throttle body with TPS. Cleaned it up really good and finally got it installed and everything back together. Took it for a drive and came back and now it's idling just below 2000.

We ran out of time and he needed to get back to Atlanta. He feels it's somewhat more manageable now and can wait until after the first of the year when each of our schedules are more open.

I did find that a local shop had done some odd piping on the EGR solenoid. The fresh air hose on the end of the solenoid had been routed over to the dual hose connector near the MAP sensor. The one that goes to the metal lines on the trunk wall. They had put a Y into one of those and connected the EGR solenoid fresh air line to it. That may be a source of a vacuum leak but I couldn't locate my replacement pieces, so it wasn't touched. This was originally an 86 4-cylinder car with a V6 and Gretrag transplanted and was rebodied with NOS Mera panels, so it didn't have the metal lines across the firewall at the front.

BTW, Dodgerunner, every IAC I've ever removed left the gasket firmly plastered to the throttle body. I had gone to Advance earlier this morning to get a gasket, but the only ones they had were with a new IAC. Paper thin. It would have taken 5 or 6 to equal the thickness of the originals.

OldBikeRacer, the 87 looks just like mine except mine still has the silver bottom. Maybe you can get up here in March and join us in the St. Pats Parade.

Thanks everyone for the input. I may be back with this one after the first of the year.