So long story short, I recently filled up my car about a week ago and notice that about a day later my car seemed to be missing pretty bad. The acceleration was inconsistent and the ride is pretty rough when the stang is in Drive and w/out acceleration. A few friends and I know it is something to do with the fuel pressure system and the engine not sucking up enough fuel or too much. I also noticed when I was in the parking garage today that when I started it up with the windows down, I smelled a decent amount of fuel.

Now I simply took off the gas cap and left it off overnight and the car ran better the next day and the "Service Engine Soon" light went off. The light has stayed off now but mustang still isn't running right...

What be the problem??

 

if it happened shortly after you filled up with gas...check the gas. are you sure its a fuel delivery issue?

 

Seems like it, I have recently filled up since with different gas and the problem is the same..What can it be?

 

I had the same thing happen to me about a month ago and it still does it!!!!! I have cjecked vaccum lines, intake for leaks, running the old gas to empty and still the same thing.

 

Check Fuel Filter. Check Spark Plugs. Check Air filter. Check PCV filter, Check vacuum lines....

 

+1 i was going to say plugs and vacuum lines myself...