Fuel pressure dropping under boost

Kybol

Kybol

New member
So i took my ty out yesterday and when i give it throttle and it tries to go into boost, my fuel pressure guage drops and the ty starts stumbling. What should I look for to make this stop? I think i have a new fuel filter i am gonna throw on, would this have anything to do with it? I did up my pressure a bit this morning, and checked for bad vac lines, but couldnt find anything.

Also where can i download a copy of datamaster, the laptop i have it on quite working.

Thanks
 
SikVSix

SikVSix

New member
Re: Fuel pressure dropping under boost

mine is doing the same. I'm going to put the racetronix relay on it (although I'm not sure if thats really a fix for the fuel pressure) and of course a new walbro 255 pump.

See Detroit Turbo or other vendors

datamaster here
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

well i did install a new 255 a couple years ago, and havent even driven it much since then.
 
SikVSix

SikVSix

New member
Re: Fuel pressure dropping under boost

filter would never hurt to try first. was the 255 a Walbro and how much did it cost? There have been problems with cheap ones and if it wasn't Walbro where did it come from?

Anybody else have feedback on if or how much the relay will help in pressure drop?
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

yeah it is a walbro, dont remember the price though.
 
Flyin Ryan

Flyin Ryan

hated cuz he drives fords
Re: Fuel pressure dropping under boost

SikVSix said:
filter would never hurt to try first. was the 255 a Walbro and how much did it cost? There have been problems with cheap ones and if it wasn't Walbro where did it come from?

Anybody else have feedback on if or how much the relay will help in pressure drop?
Click to expand...

The relay harness helps take the load off the crappy stock wiring and also keeps full 13 or 14 volts to the pump so it doesn't effect the pumps out put under load. I wouldn't think it would increase your fuel pressure at all. I'd say if your losing fuel pressure your most likely going to need to replace the pump but i'd try the fuel filter first because it's a thousand times easier to get at and cheaper.
 
sly dvl

sly dvl

Ya, it's got a Turbo
Re: Fuel pressure dropping under boost

Actually, the pump is under load at all times, from idle right up to WOT boost. The Racetronix kit eliminates the voltage drop through the stock wiring and connections, providing a higher supply voltage to the pump, which in turn will improve the volume.
Think about it; a slow turning pump (low voltage) will still create pressure, but as soon as high demand is called for (like under boost) the pump can't keep up and so the pressure drops off.

I'd do the filter and the harness upgrade before you decide to put another pump in.
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

where can i get this kit? And why would the pressure actually go down so much, wouldnt it at least stay constant, if it is the wiring?
 
sly dvl

sly dvl

Ya, it's got a Turbo
Re: Fuel pressure dropping under boost

Kybol said:
And why would the pressure actually go down so much, wouldnt it at least stay constant, if it is the wiring?
Click to expand...

The pressure will drop because the demand has exceeded the supply, so to speak.
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

Well my pump does seem louder then what i remember from driving it last year, not looking forward to changing it again...
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

hmm so either way i am probably gonna be dropping the tank?
 
1madgumby

1madgumby

New member
Re: Fuel pressure dropping under boost

You dont have to drop the tank to put the harness on, I have one. The reason your truck is dropping is that the pump is taking A crap, this is what they do just before they go out completly, I dont care if it was changed 500,000 miles ago or just 3,000 miles. seen this 100 times before. soon as boost come on it craps out, some truck I seen just stop running as soon as the boost comes on. it is not the harness but the pump, get the USA made 255 Warlbo pump NOT the cheap junk one. But for $55.00 put the harness on while your at it. I just put A new pump in 2 weeks ago along with the harness. Good luck/
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

The pump and harness are ordered, I will try and remember to let you guysy know if it fixed the problem.
 
Kybol

Kybol

New member
Re: Fuel pressure dropping under boost

Finally got the pump, and changed it out, and it is running and making boost now,
 
1madgumby

1madgumby

New member
Re: Fuel pressure dropping under boost

I know it was the pump.. Keep telling A friend that is what is wrong with hisbut he is A tite ass & wants to be sure it is the problum with A fuel psi. gauge
 
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