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Discussion Starter · #1 ·
I have a hot N/A 5.0 that has around 340hp and the fuel pump is almost 8 years old with 40k + miles on it. It's a 255lph model. My Wife and I were driving around and the car started to stutter when reved high, then as time went on the rpm's went lower and lower to cause the sputtering. It would idle fine and run great till I pushed the gas pedal more than 30% and then it just would crap out and if I let the pedal back in it would run fine. Only occures on engine load. Revs fine out of gear. New gas tank too. The pump was also making a higher than normal running pitch for a week now. The fuel filter is clean. I am convinced that this is a fuel defecit problem as I could make this happen with the application of the gas pedal and make it go away with letting go of the gas pedal. I don't have a fuel pressure gauge unfortunately (got to get one of those in the future) Do you guys think that I have correctly thought out this problem?-John

[ October 14, 2007, 01:09 AM: Message edited by: jperickson2001 ]
 

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have you checked to see if you have pressure at the injectors? Check the shcraeder (sp?) valve to see if you have pressure, be careful in case it is working.

Could be the regulator as well. good luck keep us posted
 

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John,
My very old pump (89 donor) went this summer. Much the same on and off for a couple of months. I would plan to check it out and then it would work well. It finally quit, in the Balt. Harbor tunnel.

Check the pressure, but it sounds more like a volume issue. Look at the Fuel pressure gauge kit that attaches to the shrader, but that you can see when driving. I used one from AutoZone on my daughters car. Funny looking sticking out from under the hood.

 

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My donor fuel pump went out last fall. It manifested itself as a hard start after sitting overnight, as if the FPR wasn't holding pressure. I first installed a new OEM FPR (not fun when the fuel rails are left in the car, by the way...what was Ford thinking, having the bolts come in from the bottom...anyway, I digress), but that didn't fix the problem. So, I dropped the tank (15 minutes), removed the old pump (5 minutes), installed the new pump (10 minutes), and raised the tank back up (10 minutes). Easy to do, just put a floor jack under the center of the tank, and let 'er rip!

My car doesn't have a hard start condition anymore, and roars to life like never before. I don't think my donor fuel pump was ever running up to snuff.

HTH,

Greg
 

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Discussion Starter · #5 ·
I have a new 255lpm comming from Summit Racing in two days. I used my down time to take care of some unfinished business and to do a little timesaver. I put an access hatch inside the trunk to get the fuelpump out of the car without dropping the tank. I tried it out and it works well. While I was at it I made a dropped trunk mod for the "triange center section". I'll be able to put my tools under the trunk now instead of in the trunk. -John
 
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