tjr1973

This happened once last year but I had forgotten about it over winter. Took my 06 GT for a drive yesterday for the first time this year. Went to pass another vehicle on the highway and stepped on the accelerator only to have it flat fall on it's face for a second. It then came out of it and off we went. The car has done this a few times very intermittently the last year or so. Sometimes on the highway passing and sometimes at stop lights....any ideas?

Jeffk

How many miles on your Mustang?
What if any mods do you have?
Have you changed the fuel filter recently?

Just a few thoughts that came to mind.

tjr1973

Has about 48000 miles. Second owner of the car and no I haven't put a fuel filter on it yet. Surprisingly, it is bone stock. Been doing appearance mods more than anything. The guy before me had it tuned with an SCT tuner as it has a SCT badge on the dash. I did talk to the original owner and everything was put back to stock.

I guess I will start with a fuel filter, but figured if it was plugged I probably would have more than an intermittent issue.

It almost feels electronic...almost so bad that it feels like the car dies for a microsecond. It's weird.

ski

This is a well documented problem with these cars.
It's caused by the stock fuel pump, which tends to cavitate during long highway cruises forming air bubbles in the fuel, and causes the engine to momentarily hesitate the first time the gas pedal is floored. Afterwards, it accelerates normally. This problem can also happen occasionally when driving in traffic(Been there, done that). Replacing the fuel pump is the only cure.

tjr1973

So Ford will have a pump that solves the problem? Guess I'll price it. Thanks for the info.

Nuke

There's a TSB on the fuel pump. It's applicable to 05 thru 07 or 08 and to the V6's as well as the GT's. I was aware of the TSB when I bought the wife's '06 V6 and noticed the hesitation after sustained highway, steady-state driving and also taking off from a toll booth after sustained highway speeds. The fuel pump develops air bubles and, under heavy acceleration, they are forced out of the pump and cause the hesitation/stumble. Hers was replaced under warranty per the TSB and it resolved the issue.

One other item that will sometimes cause a brief loss of power under heavy acceleration is having the TCS on (defaults to ON).