Bad IAC??

[trailblazr81]

So most often than not when I come to a stoplight my cars idle will bounce between 1200 and 300 where it almost dies. I'm thinking its the IAC. I have about 76,000 miles on the car. Anything else I should look at before shelling out the $$$ on a new IAC?? Thanks
View attachment 429144

 

[mity2]

well, go get new IAC. install it, and see if that fix ur issue. if not, take it off, stick it back in box, and take it back. Tell them it didn't bolt up right or something. thats what i do.

Being 2000 with 70k+, i will tell you that its prolly not a bad idea to replace them anyway tho.
Also Check your vacuum line as well. I had a probrem with idle once, turned out that my PCV valve rubber groumet on valve cover was pintched, and causing small leak

 

[madmatt]

Take the IAC off, clean it with carb cleaner really well. Then reinstall it, if that fixes the problem, then you know the problem is the IAC. Then you can get a new one.

 

[Kilgore Trout]

Have the freon level checked.

 

[CobraRed_96_GT]

It's definitly something vacuum

 

[RoadconeTuning]

my guess is lazy 02's and a bad IAC combined.

 

[trailblazr81]

I cleaned it with brake cleaner (didnt have any carb cleaner) and that didnt help. I would have thought with the idle bouncing so much it would throw a code. Especially if its O2 sensor or vacuum related.

Also Im reading alot of debate over Ford replacement IAC and say one from Autozone. The dealer part is twice the cost of one from autozone. How can it be that much better? Also is a dealer PCV part that much better than an autozone one?

 

[the98stang]

I cleaned it with brake cleaner (didnt have any carb cleaner) and that didnt help. I would have thought with the idle bouncing so much it would throw a code. Especially if its O2 sensor or vacuum related.

Also Im reading alot of debate over Ford replacement IAC and say one from Autozone. The dealer part is twice the cost of one from autozone. How can it be that much better? Also is a dealer PCV part that much better than an autozone one?

try the fuel filter, TPS, and vac lines too.

I put the autozone IAC in my car, and my idle is still really sh1tty. I have no idea what the prob is...

 

[madmatt]

I wouldnt buy a new IAC if cleaning it didnt help. You can usually tell its a bad IAC by cleaning it, and it will temp. fix the prob then you know its bad IAC.

 

[mity2]

I wouldnt buy a new IAC if cleaning it didnt help. You can usually tell its a bad IAC by cleaning it, and it will temp. fix the prob then you know its bad IAC.

not true. Cleaning IAC only works with handfull of cases. Most of the time, cleaning do not fix the issue, but replace IAC does(as with my case)

 

[madmatt]

Cool, learned something new today. Thanks Mity.

 

[RandyStinchcomb]

I cleaned it with brake cleaner (didnt have any carb cleaner) and that didnt help. I would have thought with the idle bouncing so much it would throw a code. Especially if its O2 sensor or vacuum related.

Also Im reading alot of debate over Ford replacement IAC and say one from Autozone. The dealer part is twice the cost of one from autozone. How can it be that much better? Also is a dealer PCV part that much better than an autozone one?

you get what you pay for, as I've posted before the aftermarket does not make there parts fit OEM standards. if you having trouble finding a Ford one for a fair price, give me a call

 

[Mike97gt]

does it do this all the time or only when the climate control is on the a/c positions ( max a/c, a/c, mix,defrost) sometimes when you have a low freeon charge and the compressor is running it will short cycle and confuse the pcm when it does so. this can cause a idle that rises and drops like that.

is there a CEL on? if it was a vacumm leak big enough to do that then you would have p0171 and p0174 in memory. only HUGE vacumm leaks will cause a rolling idle.

If both of those things are ok then I would put a new IAC in and see what happens.

 

[Robs96]

I would agree, put on a new IAC. I recently replaced mine after trying to clean it and nothing happened, the electrical component of the IAC was toast. A short history, my car was: it was hard to start and would almost die out and then the tach would bounce around on idle. The new IAC fixed this and cost $44 and I did get it from Autozone. Try it first, o2 sensors can be a bitch.

 

[trailblazr81]

No check engine light, and I have this problem without AC on and with AC on. And it doesnt do it every time, most of the time. Ive even had it die on me when trying to parrallel park. I'll probly replace the IAC this weekend, as well as climb under the car to fix the exhaust leak. Damn JEGS brand O/R H pipe isnt sealing tight on both sides. Guess I'll high temp copper goop it and hope for the best. I had to swap back to stock mid pipe for smog and since then Ive had an exhaust leak and its been getting worse.

 

[stangGT97]

also replace your PCV with an OEM Ford one... excessive blow by will seep oil into the IAC and cause buildup + failure.

 

[RandyStinchcomb]

No check engine light, and I have this problem without AC on and with AC on. And it doesnt do it every time, most of the time. Ive even had it die on me when trying to parrallel park. I'll probly replace the IAC this weekend, as well as climb under the car to fix the exhaust leak. Damn JEGS brand O/R H pipe isnt sealing tight on both sides. Guess I'll high temp copper goop it and hope for the best. I had to swap back to stock mid pipe for smog and since then Ive had an exhaust leak and its been getting worse.

well, an exhaust leak could also cause the problems you have.

 

[jstreet0204]

well, an exhaust leak could also cause the problems you have.

+1

Exhaust leak would throw off your fuel trims, and cause the idle problem.

 

[Mike97gt]

+2 fix the exhaust leak first then go from there. I wish you mentioned that in your first post

 

[scupking]

I wonder if I have an IAC problem? The other day I went to start my car and it wouldn't start. It wanted to but would stall. After the sixth attempt I put my foot on the gas to keep the rpms up and it didn't stall. It only stalled that day and has started fine every day since. Do you guys think there is a problem with my IAC?