stalls at stop light

[gary2014]

I have a 2014 GT with a stage 2 Roush supercharger and automatic transmission. Car has been running great with no problems. Last week I was at a stop light and my car stalls out. It has been running fine since I got the JLT big cold air intake ( for a roush supercharger) and tune was installed in Sept of this year
What I have noticed was at the Idle it goes to 500 RPM then stalls. Does anyone know what the idle speed should be set to and what would make the engine stall
Thanks
GARY

 

[stkjock]

idle usually is in the 700-800 range

have you checked all the connections for the vacuum lines and joints for the air intake?

 

[gary2014]

thanks no I haven't will do that when I can clean the snow off the car(snowed last night) here in Virginia
Thanks
Gary

 

[WJBertrand]

Try the idle re-learn procedure. Consists of a cold start, leave it idle until fully warm then turn on and off the AC for a period (I forget the time). Perhaps someone has posted the exact procedure here. This seemed to cure my occasional low speed stalls.

 

[Macman45]

Vehicle speed reporting okay? I had a flaky VSS and it would flip when load was taken off coming to a light, low idle and eventually stall. New VSS fixed it

 

[ddd4114]

I've had stalling issues like this, and I've found that cleaning the throttle body fixes it. I track the crap out of my car and suck in oil through the breather tube, so I think it eventually accumulates around the throttle blade and makes it difficult for the motor to control it. In your case, I suppose it's possible that something similar is happening because you'll have more blow-by with a supercharger. It only costs a little brake cleaner and a clean rag, so it's worth trying.

 

[gary2014]

thanks to everybody that replied. I tried the Idle re-learn procedure .Seamed to sill have a erratic idle. I re-loaded the tune. It loaded slow(like it was the first time) and then took it out for a drive, didn't stall will take it out this afternoon again .
thanks again for all the replies
Gary

 

[Marble]

Has the weather changed significantly since September? It can have an effect on your tune. If you have an unusually warm day, drive it and see if it acts the same.

 

[gary2014]

the weather is crazy last week ,snow then very cold then today in the 50's will uncover car and take it for a ride and see ……..

 

[gary2014]

took car out yesterday, and Friday of last week down loaded tune again
everything ok now, didn't stall at light and idle is ok now. can't figure out why it lost its tune
thank u everybody for your advice
gary

 

[gary2014]

car started stalling again the last week of DEC. went to the mustang GURU in fredericksbug,VA and he said it was the dyno tune that I had put in when the JLT cold air was put on .Went back to the previous dyno tuner I used and that's Exactly what the problem was. He showed me the dyno specs when the JLT was put on then his . The old specs was all over the place leaned out really bad. He re -dyno it and no a problem ever since.

 

[eighty6gt]

I wonder if Doug Studdard is still alive!!?

 

[Juice]

took car out yesterday, and Friday of last week down loaded tune again
everything ok now, didn't stall at light and idle is ok now. can't figure out why it lost its tune
thank u everybody for your advice
gary

When I first got mine running, it would run fine for some time(roughly 2 tanks of fuel), then my idle would start surging as adaptive trims were "learning". No CEL on. That could be an explanation of why it would seem the car " lost" the tune. A few minor tweaks took care of my idle.

 

[406guy]

car started stalling again the last week of DEC. went to the mustang GURU in fredericksbug,VA and he said it was the dyno tune that I had put in when the JLT cold air was put on .Went back to the previous dyno tuner I used and that's Exactly what the problem was. He showed me the dyno specs when the JLT was put on then his . The old specs was all over the place leaned out really bad. He re -dyno it and no a problem ever since.

So it was the tune? Glad you figured it out.

I was going to wild guess this and say fuel filter. It's easy to miss, as newer cars don't have them. I perfer to replace mine every 40k.