Hi everyone,

I have an 07 4.0 Mustang that I purchased new. It has 80k on it and recently after a long cruise on the highway it has a tendency to hesitate when you try to accelerate at all. Each time this happens turning it off and letting the car sit for a few minutes resolves the problem for the time being. Each time it has happened it has been after about a 100 mile cruise on the highway, with the exception of one time that was only about 20 miles, but that time the tank was almost empty.

One of these times it also returned codes indicating low fuel rail pressure and that it was running lean.

I have a question regarding the fuel pump TSB Ive seen on here regarding this problem. I see that they indicate this is only a problem in the 05-06 mustangs, has anyone with a newer model had this problem and it was in fact the fuel pump? Im just hesitant to put out the $300 for a new pump before I get some more info.

Thanks in advance.

 

It's a common issue, but I don't really have issues with it. It's been years, since I've even had it happen. I've heard of it happening on 07+ models, but I've also heard that the TSB isn't a 100% fix. That's why I've never bothered to pay for the TSB.

If it's not a frequent issue for you, then I wouldn't bother unless you have extra money laying around.

 

We had the problem on our 06 V6 and the TSB fixed it 100%. I recall it was a new fuel pump and a PCM reflash.

 

I have an 07 GT/CS & last spring after engine got warm it woul start to buck & run real bad under any load then die , I'd have to let it cool down before it would even start.
I then tried abottle of Techron in with the fuel to help clean the injectors up, then cleaned the throttle body as well the MAF sensor , ran better for a while then it all came back 😠 took out all fuel injectors and tested & clean all good ?
So I ordered a Delfhie fuel pump same as ford but half the cost .
My son Nathan & I put it in yesterday & you Want a new O -Ring for best seal. Low tank on fuel, remove pump relay #21 under hood & even battery cable , then pop out the rear seat & main pump is on drivers side, pust & lift black circular cup to pop out , disconnect power from pump red clip push & pull, I then tied a string around fuel line next before disconnecting incase it fell inward, disconnect & put a cover over pump outlet , oh wipe & clean area with cloth first.
Then upon repacement set in new o-ring set in pump careful float is out side of box in tank where pump would sit, there are two notches that have to meet for pump to seat proper then set lock ring over and start back clockwise to start to lock , Be very sure each part on ring catches before tapping back into place , if you miss one & go to fill us gas will pour all over , view to be sure its inplace with flash light , rehook fuel line & remove string then reconnect power.

You may want to leave seat out until you try a fill with gas to be sure, cycle key on off about 4-5 times you will here pump charge line then it gets to just a click, that's when I turned it over & wahoo ir ran like a sweet dream , took it for a drive to warm up engine , got on it & not hesitation at all .

By the way I could have just removed stock pump , cleaned it all up & collecter sock on bottom but I went new.

 

Dirty pump pickup /sock