Vernon Tull

I've read the threads on the fuel pump problem of the 05-07 GTs being hesitant and even stalling out after a long cruise, but is that the same problem as this: after a long cruise, I come to a light and stop; upon the light changing to green, the car doesn't immediately respond to the gas pedal but hesitates for a second or two before quickly launching forward in an unsettling way. Any insight?

StartMeUp

I had my fuel pump replaced under the TSB due to this problem and you are describing the same behavior I experienced. So, yes, I'd say it's the same problem.

okbfd

Hmmm.....I will have to check into that. Mine did the same but actually backfired....loudly.

StangPilot

It's the same thing. My car was doing exactly that. I would drive around 50-75 miles on the highway, then come to a stop on the off ramp. My car would not respond when I pressed the gas and then would actually jump and hesitate again.[:@]Get the fuel pump replaced. You are getting air bubbles in your air pump which causes the hesitation.

bluene05GT

I wonder if that's my problem. After warming up and running for 15-20 minutes, I let up on the gas and it dies.

Vernon Tull

Thanks, gentlemen. This is good information, and I intend to have the dealer replace the fuel pump.

I did read, however, on another forum that a similar problem to the one I've described above is the result of the "drive-by-wire" feature; forgive my ignorance and lack of mechanical knowledge, but what exactly is "drive-by-wire" ? Thanks.

tientran

It may be a different story, but I would like to post. It may help somebody. I had a problem with hesitationin the past. After pressing gas pedal, the car hesitated for a second and then accelerated strongly. Just like inCars.com, a professionalreviewed it :"After pressing gas pedal, the car has no power and suddenly too much power."I looked in the MF. Many peoplesaid that it was throttle body lag and suggested that we should turn the ignition ON( not start),wait until all lights OFF, press the gas pedal slowly down to floor, release the pedal slowly, turn offand then start engine. I did it and it worked for about a week, then hesitated again and I had to redo. But,after installing dual exhausts, I don't have the problem any more. I really don't if there is any relation between dual exhausts and hesitation.( My car is V6).

Vernon Tull

Good detail, Tientran. Thanks for the input.

elburrito99

Yeah, that's the throttle reset procedure:
https://mustangforums.com/m_2616020/tm.htm

Apparently, some of the throttle lag we experience happens because the Mustang's drive by wire system "learns" how we drive our car and then attempts to make adjustments to our car's throttle response.

bascho

Hesitation On Accelleration After Long Cruise - TSB 06-9-9

It's the fuel pump.