So my stock powertrain 05 Mustang GT 5sp was doing some strange things at autocross today. When turning hard left, the engine would pick up a bit of a misfire on one or two cylinders. Basically the engine seemed to crap out and then run well. Almost felt like it was either starving for or getting too much fuel.

There was about 1/3 a tank of fuel in it, so I don't think it was too low. I have run lower before for autocross events and never had this problem. Fuel filter was changed out last year. The car has about 65k kms on it (approx 40k miles).

This would only last about 2 seconds and it always happened at the same turns, hard left, so it could be fuel sloshing around, but again, I don't think that is it.

I am going to pull the plugs and have a look at them. Could the fuel pump be on the way out? At a loss and looking for advice.

 

I forgot to mention that this problem happened at Wide Open Throttle (WOT)

 

Not sure if this would apply, but with one of my other cars I would get something that felt similar but was due to oil sloshing up and hitting the crank.

 

No, definately not that. With my side exhaust and the window open you could hear the engine misfiring. Can only be spark issue, or fuel issue; now just to figure out what is causing it. Not easy to do because the car is driven normal the rest of the time. It is very difficult, if not impossible, to recreate this problem on the street.

 

I've had issues multiple times during open track days where the car will choke and eventually die after a hard corner with under half a tank of gas.
Doing the fuel pump reset procedure on page 161 or 163 of the owner's manual cures it like it never happened. I always head to grid with at least 3/4 of a tank now.

Edit: I had my fuel pump replaced in '07 to cure the "engine stumbling after a long cruise" TSB. Filter changed at 20k miles.

 

Sounds similar to my problem. Do you remember if it would do it turning left (hard) or other or both directions?
Not having an owners manual handy at work, is that reset procedure the fuel shut of switch that is normally supposed to trip in an accident?

 

I've had it happen in both directions.

Yes, that's the switch. Gotta turn the car off, press the button in the driver's kick panel (hard to do with a helmet on!), turn to "run", then off, then start up and go.
I think the "run"/off step may be able to be skipped, manual says to use this to check for leaks. Not sure if the computer recognizes the sequence.

This only started happening for me once I started running R-Comp tires on track (Hoosier R6/Nitto NT01)

 

So did your car actually quit running? Mine only misfires for a short time, 2 or 3 seconds during a really hard corner, and then back to normal once I straightened it out.
From your comment it sounds like your car completely died.

 

Yeah it would misfire and run very very poorly for like 20 seconds, if I don't shut it off, it dies.

 

Well that explains another problem I had last year. I thought the engine was clacking away after a long hard left hander into a stop box because the oil had sloshed to one side of the pan and starving the oil pick up. Now I think it was this fuel shut off problem.

I would like to know what Ford's engineers have to say about it, not to admit a error on their part, but to find out the best solution.

 

Me too, but the probability of that response is relatively low. I'd like to know if the FR500S uses a Fuel Cell or not...if it uses the stock tank, how do they deal with this issue?

I know the FR500C uses a fuel cell so this is not an issue for them...