New IAC didn't work ??

RandyStinchcomb · Nov 16, 2006

Kurgan said:
Dangit Randy! Stop tryin to make me order more parts!

Cha-Ching I just did

bluextc · Nov 17, 2006

It's definately related to the a/c. I tried it without the heat or air on, had no problems. Turn the heat on, the idle gets screwed up. Turn it back off it stops immediately. Going to figure out how I want to handle it this weekend, and just leave the heat off til then.

propaganda382 · Nov 17, 2006

IAC? Idle prob for me also

30% of the time i will go to start my car and it will not stay running unless I rev it and hold my foot on the pedal (only does it when engine is cold), after about 20 tries of starting it, it will finally idle normal w/o stalling. Started this 2 years ago, stopped doing it for a year, now its acting up again. Also, can someone explain to me what an IAC is, i want to see if i can fix this bull****.

the98stang · Nov 17, 2006

propaganda382 said:
30% of the time i will go to start my car and it will not stay running unless I rev it and hold my foot on the pedal (only does it when engine is cold), after about 20 tries of starting it, it will finally idle normal w/o stalling. Started this 2 years ago, stopped doing it for a year, now its acting up again. Also, can someone explain to me what an IAC is, i want to see if i can fix this bull****.

You car is most likely working when hot because the IAC's tend to stick when the engine is cold, causing the crazy idle issues. You can try cleaning it first and see if it's the problem. It is located right in front of the plenum and has a black connector connecting to it (the plenum has a stang pictured on it if you dont know what a plenum is). There are (2) 8mm bolts holding it in place. Disconnect the black connector and unbolt it. The IAC can now be cleaned with carb cleaner. Cleaning the IAC is just a temporary fix though. If you clean it, and the problem goes away, you know its the IAC. Then you can replace it with a new one. I would recommend the Motorcraft IAC. I bought a brand new one from Autozone (Wells brand) and that thing sucked a$$ . So I put my OLD IAC in, and it ran better than the brand new Wells IAC. Hope this helps...

Tanner

GSP · Nov 17, 2006

bluextc said:
It's definately related to the a/c. I tried it without the heat or air on, had no problems. Turn the heat on, the idle gets screwed up. Turn it back off it stops immediately. Going to figure out how I want to handle it this weekend, and just leave the heat off til then.

vacuum leak

hotdog71 · Nov 17, 2006

One thing to note is you should run your A/C at least once every couple of months for a few mins so that the a/c fluid can lub the o-rings in the system.
All the joins have a rubber ring in them and the a/c fluid lubricates them as it circulates around the system when they don't get lub'd the dry and the fluid evaporates.

Also Freon is a banned substance now so all a/c's should be using CFC free fluid can't remember what replaced it though

bluextc · Nov 17, 2006

GSP said:
vacuum leak

How to I check for this??? (or rather find out where the leak is, if that is it). Sorry again for the idiot questions... as I always try to say in these posts, I am new at this and trying to learn...

jstreet0204 · Nov 17, 2006

bluextc said:
How to I check for this??? (or rather find out where the leak is, if that is it). Sorry again for the idiot questions... as I always try to say in these posts, I am new at this and trying to learn...

Don't worry about looking for a vacuum leak. It sounds like you've narrowed it down the the a/c system. Get that fixed, or unplug the switch for it and you should be fine.

DTNODYA · Nov 17, 2006

propaganda382 said:
30% of the time i will go to start my car and it will not stay running unless I rev it and hold my foot on the pedal (only does it when engine is cold), after about 20 tries of starting it, it will finally idle normal w/o stalling. Started this 2 years ago, stopped doing it for a year, now its acting up again. Also, can someone explain to me what an IAC is, i want to see if i can fix this bull****.

My car used to do the same thing. It would sort of crank, like lub..lub..lub.. then it would stop. It would do that for at least 5 or 6 cranks when it was cold before it actually started. My fix was a simple one and I don't know why exactly it worked but try this: When you start your car, instead of cranking it, just turn the key to the run position and listen for the fuel pump. After it makes its noise, turn the key back off. Then turn it back to run, let pump do it's thing and try to crank it. Mine fires right up if I do that.

After reading your post again I noticed that what I wrote may not be relevant to you ... I'll leave it in case someone else finds it useful..

madmatt · Nov 17, 2006

Hmmm, I think mine may be a/c related too, but I KNOW my system is full, it was just redone, and the problem was occuring before it was redone. Could this just have to do with my compressor? Also, when this occurs, if I turn off the car, it gets better.

blacksheep-1 · Nov 17, 2006

IMO you can check 4 things, 1. Clean the IAC as has been discussed, it should work better and that would tell you that you are on the right track. 2. the a/c switch can wreak havoc with the idle as well, a low refigerant level will do it, as stated, they can usually be adjusted by the screw in the middle of it once you pull the plug off of it. 3. If the car has a tough time starting in the am, and you have to cycle the key, then the fuel pressure is bleeding off, or more likely, the fuel pump is on it's way out. Basically what you are doing is cycling the pump (just as you would if you had the fuel rails off) and you're building up fuel pressure.
4. vacuum leak, I'm just not feeling that, 4.6s don't seem to have a big problem with them, but it does pay to check it out, let's face it Vac leak is probably the cheapest to fix, so spray some of the vacuum lines with gumout lubricant and see if the idle changes (WD-40 I think is still flammable).

Kurgan · Nov 18, 2006

bluextc said:
I tried it without the heat or air on, had no problems. Turn the heat on, the idle gets screwed up. Turn it back off it stops immediately.

My symptom was that the idle didn't cycle up and down until I turned on A/C or front defog. Even after I turned it to OFF on the dial, it would still cycle the idle up to 2000 and back down to normal until I turned off the engine and started it back up.

New IAC didn't work ??

RandyStinchcomb

New Member

bluextc

New Member

propaganda382

New Member

the98stang

Active Member

GSP

New Member

hotdog71

Member

bluextc

New Member

jstreet0204

Active Member

DTNODYA

Member

madmatt

Ellis Juan sympathizer

blacksheep-1

Member

Kurgan

Similar threads

New IAC didn't work ??

New Member

New Member

New Member

Active Member

New Member

Member

New Member

Active Member

Member

Ellis Juan sympathizer

Member

Similar threads

Privacy & Transparency

Privacy & Transparency