wont idle and stalls when cold.
12-02-2005, 08:21 PM
#1
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wont idle and stalls when cold.
89 mustang lx AOD. first off when its warm outside it will idle rough until the engine warms up then its smooth after driving 1-2 min. In the last week or so when i start the car it will not stay running and i have to keep pushing the gas every sec to keep it from stalling, i sat in my driveway for 5-6 minutes and it wouldnt warm up fast enough so ive been just jumping in my jeep to get to work and i havent tried it again since tuesday.It has been colder this past week at least here in SC so im basing it on now, compared to when it was in the 70's. TPS is set at .99V MAF is clean and IAC is clean. I am not having any luck searching for my subject but i will keep google searching and looking for other things to check.I drove it 2 warmer days last week and it would stall 1 or 2 times and idle rough for the first few minutes and once my engine temp came up it was fine. Any things to check would be appreciated.
12-03-2005, 12:34 AM
#2
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RE: wont idle and stalls when cold.
also the timing is at 13 and a full tune up was done when i got the car last year but it seems to be weather related. I didnt have it on the road last winter and it was always cold-blooded even in the summer and i usually only drive it about 2-3 times a week maybe 15 miles because everytime i fix one issue i get another problem. spending weekends working out issues just to make it reliable to drive during the week is getting old.
12-03-2005, 10:45 AM
#3
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RE: wont idle and stalls when cold.
Probably the IAC (Idle Air Control) valve. They get carbon buildup and stick. Look at the articles here; http://www.muscularmustangs.com/maintain.php . Particularly article 1. Sometimes you can clean them and they will work, but I have invariably ended up replacing them.
What part of SC you from, I'm in Spartanburg county.
What part of SC you from, I'm in Spartanburg county.
12-03-2005, 11:06 AM
#4
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RE: wont idle and stalls when cold.
I have already been to that site and it was cleaned about a month ago but it really didnt look dirty and i sprayed it down anyway, i will take a closer look at it, I just dont understand how it is supposed to work. Thx for the reply.
I am in sumter, sumter county.
I am in sumter, sumter county.
12-03-2005, 11:38 AM
#5
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RE: wont idle and stalls when cold.
The way it works is that the computer opens it as much as needed to let air bypass the closed butterfly valve in the throttle body at idle. If you notice the two holes in the throttle body, one is on either side of the butterfly valve. As I said earlier, I've pretty much always ended up replacing them when they go bad. Very little success making a stuck one work. You also need to make sure the holes that go to and from the IAC in the throttle body are clean. Sometimes they just go out, even without being all that dirty. Based on your description of symptoms, I'd probably just try replacing the IAC and making sure the holes are clean. Also, make sure that the gasket is installed properly when you change it. A leak will screw up the idle also.
12-03-2005, 12:19 PM
#6
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RE: wont idle and stalls when cold.
this morning i pulled it off and disconnected the motor from the valve and it does move back and forth freely i think i will try hooking it back up without the motor attached and see if the motor does anything, otherwise i just looked it up and advance auto parts has one instock for $50.
12-03-2005, 01:02 PM
#7
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RE: wont idle and stalls when cold.
i'm with gtragtop. You'd be best changing it out. I had a similar problem awhile back and it took me forever to fix it. The new IAC I bought was also bad, so, when I went for another one, worked like a charm.
It was running fine before the problem? just one day started it? check for an air leak around the tb. Might want to check the TPS too.
It was running fine before the problem? just one day started it? check for an air leak around the tb. Might want to check the TPS too.
12-03-2005, 07:04 PM
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RE: wont idle and stalls when cold.
update. Well im back after buying a new iac and immidiatley the car dropped to 500 rpm's and caught itself and rose to 1200 and did this about 8-10 times until i stepped on the gas once then it seemed to smooth out a little with a bad lopy idle. after taking it for a 10 min drive it runs like a champ and idles very smooth but it has done this for a while now so im not sure if i fixed the problem i will find out tomorrow morning when i start it and see if it will stay running. Cold Blooded B!T(#
12-04-2005, 01:47 AM
#10
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RE: wont idle and stalls when cold.
Don't forget to reset your computer. It may have learned all kinds of bad habits when the IAC wouldn't respond. Just disconnect the battery for around 30 minutes. Also, check the salt and pepper shakers. I have read numerous post stating that a bad connection in those harnesses could cause some strange idle problems. But first, be sure to reset the computer if you haven't done so.