03 Cobra keeps stalling while stopping. Help appreciated.

[amurray7777]

I bought an 03 Cobra in August with a VMP TVS blower and an E 85 fuel system. Car runs great. Had to sort through some alternator issues and got all that worked out. Put in a T-56 Magnum 26 spline and an RXT.

For some reason, the car used to occasionally stall when coming to a stop. Especially, a hard stop.

That went away after the new alternator went on and now it’s back. It stalled on me 4 times today. Twice while turning in neutral, and twice while stopping. I can see the idle rolling and hunting before it happens. Sometimes it just drops and dies. Yesterday, it was fine all day.

My Fox used to idle roll and I adjusted the IAC, and the problem went away. I watch my XCAL 4 and the desired idle is set at 816 while warm.

It eas tuned at Palm Beach Dyno and they are awesome. Very, very busy. The old owner said he never had this issue.

I’m leaning towards a dirty IAC, or MAF, but I wanted some opinions. It’s getting worse and it’s frustrating the hell out of me. Any help would be greatly appreciated.

 

[SilverNotch]

I’d say a bad maf or the maf is getting in metered air. I list a cai air filter and mine did that.


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[98 svt]

I had the same problems coming to a stop in my 98 it was the speed sensor on the trans, but that doesn't help you.

 

[amurray7777]

I had the same problems coming to a stop in my 98 it was the speed sensor on the trans, but that doesn't help you.

Had a buddy with a 98! That’s what got me hooked on wanting a Cobra!

 

[01yellercobra]

So it's done the stalling thing the whole time you've owned it or it just started recently?

 

[SilverNotch]

Mine started stalling like yours. I changed the iac, that didn’t work . Then I found that my in fender air filter was gone. I bought a new k&n, then it was fine.


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[lOOKnGO]

TPS

 

[amurray7777]

I had the same problems coming to a stop in my 98 it was the speed sensor on the trans, but that doesn't help you.

Had a buddy with a 98! That’s what got me hooked on wanting a Cobra

So it's done the stalling thing the whole time you've owned it or it just started recently?

its done it as long as I’ve owned it with the tune that’s in there. But it used to be once or twice a week if that. Yesterday, it happened 4 times in one day.

 

[CobraBob]

If it's done this as long as you've owned it with the installed tune, I find it hard to believe the previous owner never had this issue. But regardless, he's not going to be any help to you in your quest to find and fix the issue. Make a list of the possible causes/fixes. Go after the obvious and lesser cost possibilities first, one at a time, allowing some time to test the fix before proceeding to the next one on your list.

 

[Dave.O]

Mine did this for a while, essentially after a long highway cruise at steady throttle. After exiting to a stop/light idle would stall or bounce a couple times then stall as if it couldn’t find the proper idle speed.
Blipping the throttle could catch it before it stalled and it would balance out.
This was ultimately corrected in the tune, been fine ever since


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[hotcobra03]

I also had this issue

For mine it was the coils.
It had started jerk alot while driving,,after new coils is where I noticed the idle stayed when stopping vs bouncing or stall .

I Did not get any codes at any time ,,

I used ford racing kit of 8 ..

Other than coils,

Air leak on pcv line also caused stalling and high idle

 

[P49Y-CY]

the only time i had this happen to me was after i changed to a k&n intake kit. the car was originally tuned with a php intake, and when i switched over it didn't like it. it would stall as i was coming up to a red light. went back to the php intake and never had a problem again.

 

[amurray7777]

I also had this issue

For mine it was the coils.
It had started jerk alot while driving,,after new coils is where I noticed the idle stayed when stopping vs bouncing or stall .

I Did not get any codes at any time ,,

I used ford racing kit of 8 ..

Other than coils,

Air leak on pcv line also caused stalling and high idle

I have no jerking. The car runs perfect and if I see the RPMS drop slowing to a red light, I stab it quick and it stays where it’s supposed to. Super annoying.

 

[amurray7777]

Mine did this for a while, essentially after a long highway cruise at steady throttle. After exiting to a stop/light idle would stall or bounce a couple times then stall as if it couldn’t find the proper idle speed.
Blipping the throttle could catch it before it stalled and it would balance out.
This was ultimately corrected in the tune, been fine ever since


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I’m think unless I have a sticking IAC, it’s probably in the tune as well. The old one er didn’t drive it much like I do, so he may not have experienced it. Or not as much anyway. I will get to the bottom of it, but it’s a pain in the ass to get the tuner to look at it. They are so busy working on GT500’s.

 

[Dave.O]

Mine was able to do it remotely, he had previously tuned mine on dyno. So he just emailed me an update


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[01yellercobra]

I'll say it's the tune. Previous owners have selective memories about their cars.

 

[amurray7777]

So it's done the stalling thing the whole time you've owned it or it just started recently?

Yeah it would do it occasionally. Now it’s becoming much more often.

 

[hotcobra03]

Some pics of engine bay may help ..
Vacuum routing,mass air sensor clocking,

I've driven mine to death, but drivability has been just about flawless,

O2 sensors have also did stra ge stuff,,
Having long tubes may be factor,
I've had times the idle would search after a long drive on highway to exit at a traffic light,

While waiting I would have to hold rpms up or Rev.
But if I was to use tuner and reset pcm car would idle perfectly again.

I'm using Diablo prediator to do this


Have any other codes appeared time you owned car?

 

[amurray7777]

I'll say it's the tune. Previous owners have selective memories about their cars.

You can say that again lol!!

 

[Blown 89]

Sometimes the throttle bodies stick on new edges. I had the same problem on my 01, it would stall coming to a stop at lights. It's at least worth looking into.