What is an idle air controller (IAC) I have been told on this forum that I need one but I don't know what it is, where it is, or what it does. Can I order It from Ford? Is somewhere else cheaper?

 

IAC -Idle air control valve,It controls the amount of air during idle at start up.Also is used until engine reaches normal op temp.
It is located on the back side of the throttle body on our trucks on some cars its mounted in the intake runner directly behind TB.
Common symptom is a searching idle or a stall after start up when cold or hot.
A slight press of the go pedal on start up that keeps the vehicle running is a indication of it failing or the small ports to it are clogged with carbon.

Yes Ford has them or can be gotten aftermarket.I prefer Ford .

Don't be fooled thinking the IAC causes a rough running engine ,their are other causes for that.
Rich

 

Take a look in my gallery. I have instructions with pictures for the IAC removal and install...that are from my FORD Service Manual.

Good luck...

biz

 

Rich, I'm not totally disagreeing with you, and you being a "real" tech, you might be right.

However, here's my take on the aftermarket vs. OEM issue.

Ford's original equipment is what failed in the first place. I don't think Ford ever updated/upgraded the IAC. What you buy from Ford is the same piece as what came on the truck from the factory. There might be some manufacturing changes that upped the quality control, but the chances are slim.

Over the years, I've bought many many aftermarket parts for my Fords. Much of it had the Ford script logo on it, and in many cases, even a Ford part #.

Many people will say that the aftermarket parts are what were kicked off the assembly-line because they didn't meet "Ford's specs", and get sold off to the aftermarket. I know GM/Chevy techs that say that all the time about using Delco stuff.

I personally think this is plain BS.

I would not be afraid to use an aftermarket part.

Case in point: Go to ford to price a rear u-joint. List is $69.40. Go to the local heavy-duty truck parts, get a Spicer u-joint for $15.

What's the difference? The blue box with the Ford logo on it. Open the Ford box, the u-joint is a Spicer. Maybe.

Do you really think that $15 u-joint got kicked from the assembly line because it didn't meet Ford's specs?

I used Standard brand COP boots when I did the plugs on my V10. They were superior to the ones that were put on at the factory, with another sealing lip around the top. Cost at jobber price, $3/ea.

Hmm... another aftermarket part that was kicked off the assembly line because it didn't meet Ford's specs? Nope, a part that was engineered to exceed Ford's specs. And it's cheaper.

It's been my experience, with Standard, Holley, and many other "aftermarket" parts that they are either Ford parts in the box, or a part that was engineered to surpass the original's quality because they knew the part stank from the factory.

Now don't get me wrong. Autozone/Auto-Barn/Aid-auto, etc selling white-box parts with their own name on them, well, it's very possible these are sub-standard parts.

But Standard brand, Holley, and lots of other well-known name brands are selling parts that are at least as good as the factory Ford part. And cheaper.

Sorry for the dissertation, but I had to bring up the other side of the coin

 

Art,I think that the last part of your note is more what Rich was saying... that the typical AutoZone mass market aftermarket sources are more and more from off shore sources that violate patent law and provide a visually inferior part...

I have seen the generic IAC for low bucks and it is a horrid piece of cast and machined engineering... in this area I would gladly pay Fords relatively low cost for that specific part...

I do fully understand your point and I always have "better then FoMoCo" advice for my firends...along the same lines as your plug boot comparison...

 

If I'm acting at all wishy-washy lately, let me know

 

Since this thread is about the IAC and I think my problem is the IAC im gonna ask it here. After starting my truck after sitting over night and put it in gear it wants to die. The RPMs drop and it almost stalls then bucks back to life and takes off with no other problems. I already had the 90* PCV hose replaced several months ago. So what do you all think? IAC? Other vacum leak? Truck runs great other than that, and only does it on cold start conditions.

 

Definitely the IAC...

 

Is there a T.P.S( throttle position switch) on our V-10's? I had to replace one on my 96 f150 years ago, symptons were eratic idle. and if I reved it a few times , it would settle down for a while and start acting up again, it was an easy fix. I also cleaned the IAC on that engine, as it was all gummed up after 200,000 miles. It worked for a while, but I bought an aftermarket one from a NAPA store, opened it up and the ford emblem was on the mech. part, and I think Bosch was the manufacturer of electric component. It was a long time ago, but it worked OK.

 

Thanks Krewat. I always like to check my first thoughts here instead of throwing parts at something. New IAC on Monday.