gossmustang

Hello everyone I have a 2003 gt 4.6 2v only mod is exhaust
my problem is fuel presure drops on wot and mild load between 2ooo-3000rpm
thinks I have done back probed frpm power to unit battery voltage 12.8
fuel pump battery voltage but fuel presure gauge drops off to 5psi engine sounds as if someone pulled the life out of it but does not stall
I gave it 12v to the pump directly with frpm unplug same condtion
any one have any ideas ??????

kugzgt

try writing complete sentences and you should receive some answers. i have no idea wtf you're trying to say.

gossmustang

Hello everyone I have a 2003 gt 4.6 2v

My problem is fuel pressure drops a full throttle (wot and mild load between 2000-3000rpm)

Things I have done
Checked frpm power to unit battery voltage 12.8
Checked fuel pump For voltage ok

When condtion is present fuel presure gauge shows fuel psi drops off to
5psi engine sounds as if someone pulled the life out of it
but it does not stall

I gave the fuel pump a direct 12v with frpm unplugged
same condtion present
The fuel pump has been replaced
any one have any ideas ??????

cliffyk

Not a clue--with the FPDM disconnected and +12V directly to the pump it should have been running pig rich...

Brent Kline

I am having the same issue. I have a 2003 mustang gt with a v2 si trim. I was driving down the road and the car just fell on its face almost stalling and then the check engine light came on . the code was p0190 frps circuit malfunction. replaced the sensor, same problem still. replaced pump . with walboro 255 same problem. brought the car to dyno to tune it and under any load the fuel pressure just drops from 40 at idle at rail to 25 or less. makes no sense. got another pump from leathal performance 344 lph and a pprv delete kit . now car doesnt have a p0190 frps code. it just does the same thing. under acceleration the fuel pressure drop s instead of rising. anybody have a clue as to what is going on. already checker fpdm and it was fine. no vacume leaks. never had problem until 2 months after blower install. any help would be greatly appreciated!

Brent Kline

I fixed my fuel issue with my car 20 min ago. I have alot more mods including fuel mods. but it is possible you have the same issue I did. First things first. do you have your possitive pressure releif valve hooked up still? Second what pump did you install? size and brand? the plastic nozzle with the 2 ports on it that pushes down over the fuel pump nipple, is what was causing my fuel pressure drops under partial throttle. for what ever reason fuel was pushing back towards the pump and not sealing. I also have a pprv delete what I did to fix the issue was run a fuel line hose that comes with the new fuel pump directly from the pump to the hat on the top of tank. that way no fuel can bleed off. now my car is running like it used to and better becuase it holds pressure. let me know if that helps.