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Discussion Starter #1
I am running about 76 to 78 pounds of fuel pressure.Is this too much to run on a daily driver? Mods are 4" exhaust,AFE stage 2 intake,GTP38R turbo,fuel rail crossover,Walbro 392 inline fuel pump,DP tuner,boost fooler, etc. Injectors are stock.
 

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Yeah, to much fuel pressure. It should be around 65ish.
 

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Will start blowing out seals.
 

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How hard is your truck to start with the pressure that high? Whenever my truck is hard to start, almost to the point where it sounds like a dead battery when trying to start, i'll pop the hood and see my fuel pressure is 72-74 psi. If I turn it down to about 68 psi it'll crank right up no problem. At OP temp i'm running about 65 psi.
 

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Discussion Starter #6
It starts fairly easy.I have fuel rail crossover and probably have the wrong spring installed.When I'm idling it runs 76 to 78 psi.Cruising it may drop to as low as 72.
 

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Its not going to blow up... Its not going to blow seals... It over works the pump is about it.

It can cause leaks in the fuel bowl...

Every injector likes a different fuel pressure... I ran stock injectors for years at 72 psi... Then 180/80's at 62, then 238/80's at 68 and 250/200's at 64...
 

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^yep. this is correct.
 

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Discussion Starter #9
So to be safe it probably would make sense to lower the fuel pressure a bit?When lowering fuel pressure don't you lose some horsepower?More fuel means more power.That is what Ive always thought.
 

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There's really nothing "unsafe" about an additional 10lbs of fuel pressure, I'm not sure I see a downside, with the possible exception of working the pump a bit harder.

The boost in pressure has no HP advantages as the pressure delivered to the cylinders is controlled by the injectors using the HPOPs output and what that "intake" fuel pressure is to the injector becomes insignificant. The advantage might be, because the 8 & 6 cylinders fire in sequence, making fuel delivery to the #8 slightly starved, you want the most fuel available there.

I doubt, on a stock truck, it makes any difference though ;)
 

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Discussion Starter #11
Ok I have the Riffraff FRx kit and I haved installed the gold spring which says fuel pressure of 62-65psi.I have a mechanical fuel pressure gauge and a electronic fuel pressure gauge.At idle they both read about 84psi.I have installed all three springs and they do not vary that much at all in fuel pressure.At WOT pressure only drops to about 77-78ish.Now the only thing I can think of is that I installed the Walbro 392GSL fuel pump recently but it still shouldnt run that kind of pressure.The truck runs really well and starts really well currently.With the smaller fuel pressure spring of 55-58psi,my truck seemed very lazy and didnt start as well(it cranked over several seconds before starting).What should I do about pressure or am I ok to run an everyday driver/lead foot like this?Is there anything I should beware of and can the fuel pump that I have handle this pressure good?
 

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i have actually recently been involved in a heated discussion on this and to be honest my truck is a fan of the 72psi i have running to it not saying thats right but imo thats as high as i am willinto go maybe higher than i am completely comfortable with but the only thing you gain or lose performance based in these trucks due to fuel pressure is if you have alot of air in your system if you see a big improvement between 60 psi and 75 psi it is due to the fact that you are compressing the air in your fuel and inherently getting more fuel into the injector but if you have a good filter setup that removes the air you wont see that much difference if any at all
my suggestion take a look at your fuel system and make sure you are not sucking air anywhere also look into the hutch and harpoon mod this will definatly help your situation out
 

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As you raise the pressure, the performance will groww whith it up to 105psi. After 105psi the HPOP can't overcome the fuel so you'll need to reprogram the IPR to 3400psi to be able to run up to 150psi in the rails. I have a high mileage truck with over 400,000mi set at 105psi.I have never had a seal problem yet. Wrong thing to say!! The neet part about the high fuel rail pressure is the elimination of vapor and air.
 

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can u back up your claims with real numbers i noticed you posted numbers since we last talked about your fuel pressure assumptions but untill you show us some real before and after numbers please stop posting the high fuel pressure making any difference ifyou made it work good for you but these vehicles were very specifically designed to not run on or need high fuel pressure and if someone not knowing any better actually listens to you and tears something up or is left stranded by the highway due to your un backable claims well i would hate to be you my friend to the op not a single person on here making serious power nor any reputable tuner will ever recommend high fuel pressure 60 to 70 psi seems to be the consensus stick with that and youll be good to go
 

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As you raise the pressure, the performance will groww whith it up to 105psi. After 105psi the HPOP can't overcome the fuel so you'll need to reprogram the IPR to 3400psi to be able to run up to 150psi in the rails. I have a high mileage truck with over 400,000mi set at 105psi.I have never had a seal problem yet. Wrong thing to say!! The neet part about the high fuel rail pressure is the elimination of vapor and air.
This guy...don't listen to him.:tard:
 
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