Running rough..

[Hacklemerc]

Okay guys, the wife's 04 DTR has been running rough for a while. Its over 110k miles, so I thought "change the plugs," put in some new motorcraft plugs. Still runs like rough. At idle it is really choppy and rough, but when the gas is pressed the car runs really good. Thinking it may be the COP's I have reseated them, checked the gap on the plugs, reseated them again, ran injector cleaner through it, checked the MAF, cleaned the MAF. Oil changed, and it still idles choppy. Any suggestions?

Thanks,

Hack

[da'law]

Check your Idle Air Control (IAC for short) wife's Explorer did that, once replaced it was fine.

[RoyLPita]

Are the coils going bad?

[Hacklemerc]

Where is the IAC? is it easy to replace?

I don't know it the coils are going bad but thats the only thing I can really think of. I've cleaned and checked everything else. Am I missing something?

Hack

[justbob]

Two bolts, check for oiling inside and clean it.


http://i300.photobucket.com/albums/nn19/marauding4life/IAC.jpg

[justbob]

Sorry, having picture resizing issues.
http://i300.photobucket.com/albums/nn19/marauding4life/IAC-1.jpg

[Hacklemerc]

all good. I'm gonna search for it here in a bit.

[jdenning002]

Did you fix the problem??

[Hacklemerc]

HA! well yes and no... replaced the coils, car ran great for 1 day. Next day wife comes home says car is doing the same thing. Switch out MAF's. Leave Battery cable off so as to reset computer. Next day, car runs great. Next day, runs like crap. Haven't done the IAC yet. This is next on my list. As I said before when the gas is pressed the car runs wicked strong, but at idle it shakes and acts like its gonna die. Doing the IAC this weekend.

[CBT]

What's your rpm's at idle?

[jdenning002]

Let me know if that is it... I cleaned my IAC, its easy, 2 bolts and spray...

I got "electronics parts cleaner" that is what the parts store said to use, it will not leave a residue.

Good luck.

[Hacklemerc]

What's your rpm's at idle?

down to about 300 dipping to 200 range. IT gets a lope to it that makes it seem like its got a racing cam in it. If you just tap the gas at idle it will jump back up to about 800 rpm but then after a sec it will drop back down.

[MrBluGruv]

faaaaar stretch here but....

would there be any chance it had something to do with the torque converter? like trying to engage prematurely?

just a far left field idea...

[Hacklemerc]

I couldn't tell. I would think with the torque converter screwing up it would effect the drivability of the car but like I said when the gas is applied it rolls out.

[CBT]

down to about 300 dipping to 200 range. IT gets a lope to it that makes it seem like its got a racing cam in it. If you just tap the gas at idle it will jump back up to about 800 rpm but then after a sec it will drop back down.

ZOIKS! That is waaaaay too low. I'm surprised it is even moving oil thru your block, dude!

[CBT]

Have injectors flushed, and I mean FLUSHED, like on the machine at an actually Ford dealer, they will check them also for flow before and after. I had your problem (not quite THAT low on rpm's) and this fixed it.

[Phrog_gunner]

Most FLM dealers now use the BG system for cleaning the fuel injectors and your entire intake system. Theres a treatment that goes in the tank and one that goes through the air intake as well. At the dealer in NC it runs about $109 for that service. I highly recommend it. I will be getting this done as part of my 50,000 mile preventative maintenance.

[Hacklemerc]

Will call the Stealership asap. I was trying to get around all that. Will advise of the outcome. Thanks for all the help guys.

[CBT]

Will call the Stealership asap. I was trying to get around all that. Will advise of the outcome. Thanks for all the help guys.

no prob, just keep one foot on the gas, i'm shocked your car hasn't overheated turning rpm's that low, for real.

[Hacklemerc]

Its mainly highway driven. IF we go anywhere around town I drive mine. Hers is straight back and forth to work. She wouldn't know if it was overheating untill it died on her. I love her to death but car knowledge is not her best trait.

[Hacklemerc]

Ladies and Gentlemen... I think I may have it licked. After dancing around and not checking the IAC I have finally checked it. It was fulllllllll of carbon. I'm not sure as to what they are supposed to look like inside but that much carbon (I think) would be bad. I cleaned it out with some electronic parts cleaner and let it dryout. Slapped it back in and started her up. Still idles a little rough, rougher than I would like but rpms are up to about 800. I think I may just order a new one from the stealership. WE are still going to have the injectors flushed but hopefully I have it fixed.

Thanks for the help guys...

[jdenning002]

Did you try cleaning the IAC? How about O2 sensors?

[4play]

how did you make out on this?

[Marauderjack]

I have gone through several IAC's and have not had any luck cleaning them!!:shake:

I took the last one apart and it is a fairly complex piece that has a lot of areas it could fail in...carbon being the primary one!!:cool:

Get yourself a new one and you should be OK...based on your last post!!:beer:

Also, when you install it be sure to reset the Adaptive Learning by disconnecting the negative battery terminal for a few minutes!!:banana:

Marauderjack:burnout:

[RacerX]

Good article on the IAC.
http://www.p71interceptor.com/repairs/iac/