Funny Idle...

[Blkstg2x]

This is simply an FYI:
My S2 has been idling funny for a few months now. Well the other day I started it up and it died..Turned it over again..then died...Time after time..same thing. I could keep my foot on the gas and the car would run, but sounded terrible! So, I did a little research and narrowed it down to two VERY simple things. IAC (idle air control valve $60) or TPS(throttle Position Sensor $32). Today I stopped on my way home from work and picked up a new IAC and presto! It runs like a champ. The idle is much smoother and sounds just as it should. Seems to be running great..and I'm hoping the smoother idle will help the gas mileage as well, because I've noticed since the idle was soo rough, I've lost several mpg. Anyways, I hope that if people search on something of this topic, they can find a hit on this thread...I found some threads that mention IAC, but weren't closely related to this exact issue.

IAC

[vista blue]

Glad you found the problem.How's jon doing any progress on the car?HAVE GOOD ONE.

[F4iMerlin]

Good find! Very common on our model years, though not many folks know about it. I was able to clean mine with the same effect, but new is always better.





EDIT: WooHoo....Post 1K!!!!

[360Rocket]

You didn't have to buy a new one, just clean it periodically. Known issue with these cars.

[Markass]

If it was that funny, you should have just sternly told it to straighten up, and be serious.

[Roushinator]

Originally Posted by Markass

If it was that funny, you should have just sternly told it to straighten up, and be serious.

That would have saved him some $$$$.

[roushstage2]

Maybe I should check mine. My idle has been mildly rough (jitters from about 700-1000RPM back and forth), nothing too bad, just noticeable.

[roushstage2]

BTW, what product would be used to clean it?

[Bill H]

i used brake cleaner on mine. worked for a while. i finally broke down and bought i new one though.

[NoMoRoush]

Brake cleaner or carb cleaner will work. While youre at it, open up your throttle body and clean all the gunk out of there as well. Even if theres a little bit of carbon build up, it could cause the throttle plate to stick a little and effect idle and throttle response.

[RED ROUSH WA]

I highly recommend "Seafoam".I've used it on many cars and works well.
Not as harsh as carb cleaner.

[roushstage2]

Originally Posted by RED ROUSH WA

I highly recommend "Seafoam".I've used it on many cars and works well.
Not as harsh as carb cleaner.

I ended up buying some Deep Creep to clean out the IAC on two other vehicles. I will be using that, it worked well. The one thing I was thinking of though is can I reuse the gasket under the plenum (if there is one)? I was thinking about taking the whole thing off to clean it so that dirty crap doesn't go down into the engine.

[NoMoRoush]

If it isnt all torn or damaged im sure you could use it cause you dont want leaks there.

[Blkstg2x]

There isn't a gasket between the plenum and intake manifold on the mustang. I just added an Accufab Plenum and BBK 75mm TB...along with my IAC replacement.

[Roushinator]

Originally Posted by Blkstg2x

There isn't a gasket between the plenum and intake manifold on the mustang. I just added an Accufab Plenum and BBK 75mm TB...along with my IAC replacement.

Get that from Jon?

[Blkstg2x]

Yep...I had to swap him my stock parts..his insurance company wouldn't let his go like that.