Losing Fuel Pressure

Sliepnir16 · 05-07-2006

I am just wondering as if you were to lose fuel pressure what would be the symptoms? My car was sputtering and jerking at low rpms and had to be kept at atleast 3k to keep it going, and if for some reason I had to let off of the fuel, by the time I stopped It would die. I had to wait several minutes before it would start, then I would take off reeming it for another 3 or 4 miles until I had to let off of the throttle again and had to repeat the process. Im not sure if that is the problem, but my car is in the shop, and they are saying the electrical system is fine so now they are suspecting the fuel pump since the fuel pressure drops. Does this sound like a pump problem? I would leave it to them to figure it out, but they don't seem to be too familiar with the 5.0, so before I got cheered up about it I wanted to find out if the pump can even cause a problem like this. I know it can keep it from running, but Ive read other threads about people losing fuel pressure and not saying anything about the driving symptoms.
Thanks.

mustang5l21 · 05-07-2006

i pretty much say its definitally the fuel pump for the reason mine did the exact same thing last year till i upgraded. it would start to die out and if u kept on the gas good it would run till you came to a stop and then die. leave it for 5-10mins and go again for a while then exact same thing unless you left it for a long time thne it would last longer before dieing, also when warm it seemed to happen more often. but you might just want to change the fuel filter first if you never yet.

WhiteSnow · 05-08-2006

Yep that sowneds likea fuel Pump are a realy Cloged Fuel Filter why its at the shop and thay change out the fuel pump get them to add you a filter under the hood that you can see though it like a site glass that way you can allways see if your geting fuel at the motor i have one in mine works great was there when i bought the car its actuly useing Bent tubeing and fitings not just rubber hoses

Sliepnir16 · 05-08-2006

The fuel filter has been changed recently so I think that it narrows that down, and yeah it sounds to me like yours did the EXACT same thing that mine is, the longer you wait, the longer it will last and the temp makes a difference too. When it first started doing that I was about 20 miles from home, so I had to lay into it the whole way with frequent pauses when it would die, and I had to wait every time so it would run again. It sucked, but eventually I got it home. The fuel filter under the hood sounds really good, Ill have to look into that.
Thanks for the info.

mustang5l21 · 05-08-2006

you might want to upgrade to a higher flowing fuel pump so if you decide to start upgrading stuff its one less thing you'll have to do. i went with a 155lph. Let us know if that fixes the problem, i'm pretty sure it will though.

Sliepnir16 · 05-12-2006

Well, now they are saying that it is holding at 35 psi like it should. Do you still think it could be the fuel pump? He said the other day it would run and idle with no problems and idled for like 2 hours after that until they shut it off, but then a few days later it would not run. They are swamped and cannot figure out whats wrong with it, and since the vin number doesn't match, since its a conversion, they cant use the computer, but I say just get the vin of off any other 87-93 GT as it will pull up the same specs right? They don't seem to know that. The KOEO codes that I got were 15,33,15,33, separator pulse 85,96,85,86 and its a 91 gt motor and 91 everything else. If someone has a code book on this year range, Id appreciate the meaning of these codes, and Im sure 33 is egr valve which is unhooked anyways.
Thanks.

mustang5l21 · 05-13-2006

belive it or not my fuel pump is gone again. i had it checked it showed 30psi but the longer i drive it the worst it gets so another is on order. soon going to use a whole different system all together. seems like alot of people have problems with these fuel pumps .

mustang5l21 · 05-13-2006

could also be a distributor, one around here did the exact thing shuting off and stuff and we swapped distributers from a different car and it still works till this day without a problem.

Sliepnir16 · 05-13-2006

Yeah dist is stock still. Ill check it but they said its getting good spark. I think its the ECC.

BadSanta · 05-14-2006

Not being a member here at the time, I just started replacing the components that seems likely.
Replaced:
Alternator & Battery ( thinking it was an electrical problem-initially)
TFI- Ignition Module
Distributor

Took a trip from Mesa to San Diego. Ran great until the return trip across the desert in 95 plus temps. Died in the middle of nowhere. "Rested" for about 20 minutes and drove the rest of the way - slower. Noticed that the hum from the electric pump seemed louder.

Changed the Electric Fuel Pump (Test PSI was about 4-5 pounds low)
Replaced the Fuel Filter (Just Because)

Has been running GREAT ever since.

Hope it continues, as I am driving it to Chicago next month..LOL.