Please Help!! low/rough Idle and stalling 99 Mustang GT

They Call Me Juice!

They Call Me Juice!

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Please Help!! low/rough Idle and stalling 99 Mustang GT - Problem Solved

It seems for the past few years whenever it gets cold. My car doesn't want to start. I have to turn it over 20+ times to get it to barely run, then just shuts off... This usually doesn't start till it gets pretty cold, and expecially on days it snows alot... Well yesterday (not so cold) I ran out, car ran fine... came home... Left 3 hours later... was doing the stalling, not starting bullshit... Now it's idling around 600 or so... or just drops down to 300.... When i get it to stay on without stalling, and I drive... seems like it's fine except when i'm between gears it seems like it looses r's fast...

Gas tank is full, no check engine light, doesn't seem to be missing... I don't think I have a clogged filter, or bad pump cuz when it's running all shitty it smells like it's running way rich...

I've been thinking it's a MAF issue... Any ideas?
 
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Ummm a year ago or so... but like I said... it does this same shit every winter... and yesterday it was fine the first time I went out, then back to what it was doing the past few years, only a couple hours later...

I just took the MAF out and sprayed the shit out of it... put it back in, and it seemed to idle at normal, but after about 30 seconds it stumbled down to 300, and back to normal... but it didn't stall... Maybe it was dirty? Hasn't been cleaned in 105,000 miles...


Oh it also did this before I changed the plugs, and still did it after. Only seems to be when it's colder out. And when it's humid and cold
 
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didnt replace them when I did the plugs but I did inspect them. They looked fine... No check engine light... And like I said. it only does this in the winter, and has been about the last 5 years or so... And ONLY when it gets colder...
 
Sounds like mouisture in the coil boot. Just my 2cents.


They Call Me Juice! said:
didnt replace them when I did the plugs but I did inspect them. They looked fine... No check engine light... And like I said. it only does this in the winter, and has been about the last 5 years or so... And ONLY when it gets colder...
Click to expand...
 
I once had a Ranger that would be very hard to start only when cold on colder days and would run rough with rpms going up and down. every thing was fine in warm weather or when the engine warmed up. Ended up being a IAC
 
Sean said:
Sounds like moisture in the coil boot. Just my 2cents.
Click to expand...

Well looks like it's the IAC... got it started, and barely running... then I tapped on the end of the IAC, made a little vacuum sound, and back to normal... starts right up... steady idle, etc... Gonna grab a new one just in case, but that seemed to be the issue...

thanks for all the ideas though!
 
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