fuel psi issues?

97cherokee · May 9, 2016

hey guys i got gauges installed on m truck the other day and idling i hav e 60-65 psi, cruising down the road with no load or hill it stays at a steady 61 psi, if i place it under a load going up hill i have seen it drop to 45 psi under heavy throttle. i am running swamps stage 2 split shots, there tunes on a 6 pos ts chip. is it normal to see the fuel psi drop like that under heavy throttle? one response i got on another forum is i need to do the hutch mod.

mikeeg02 · May 9, 2016

A little more information on your fuel system would be helpful. What have you done if anything to the fuel system? Regulated return? FRX? Something else? What year truck?
Hutch mod is a good thing to do. Takes the mixer out of the equation in the tank, helps with air.

97cherokee · May 9, 2016

no mods to my fuel system, truck is 2001 with 316k.

sqrlgtr · May 9, 2016

I've always heard anything below 45psi was not good but some of these other people are alot more knowledgeable than me maybe they will chime in.how do you like them stage 2 split shots?I have been wondering about those for my truck.you bout the only one I've heard of running them.

CarportMechanic · May 9, 2016

Yeah Ive herd 40, 45 and 50 are as low as you want to go. Before my fuel system I just did my best to stay above 50 to stay safe.

As mentioned your screens in your tank my be clogged so a Hutch mod would be a good idea (well its a good idea either way).

If that dont fix it then a new FPR would be a good idea. I believe its Diesel Orings that makes a nice billet FPR with 3 different springs to change pressure to your desired level.

If neither of those work it may be your stock pump is getting weak.

Do you know the size of the injector? Like stock is 150/146 and, mine are 175/80 meaning 175cc of fuel with the nozzle being 80% bigger than stock. This will help us tell you if a stock pump can supply enough fuel. Im not familiar with the stages.

97cherokee · May 9, 2016

i believe they are a 40 percent larger nozzle, not sure on the cc rating though

Dmstrucks02 · May 9, 2016

97cherokee said:
i believe they are a 40 percent larger nozzle, not sure on the cc rating though

Is this a new issue? The tiny stock plumbing doesn't help, and the screens in the fittings at the heads are restrictive. A full regulated return system is a good mod

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Arisley · May 9, 2016

Yep, another restriction is the valve in the standpipe in the fuel bowl. Easy peasy to gut it. Pull the stand pipe and poke out the guts with a screwdriver.

Here is a great write up for Hutch and Harpoon mods. By the way, Hutch and Harpoon are people. HutchinAugusta and Maroon Harpoon. Great guys.

Those fittings in the heads can be removed, the valves can be removed from the fittings and then bore them out a little. Make sure you clean them spotlessly after boring.

MoonShiner · May 11, 2016

first thing I would check is those 2 fuel screens in the pick up.....my F350 started acting up, losing power, running like crap.....I pulled the pick up out of the tank and the screens were completely plugged with gunk...cleaned them and it's back to running like a champ.

I had it easy though....I just raised the dump bed and there is the tank...easy access..
dropping the tank is a PITA

rsater1 · May 11, 2016

I was told not to pull,, fuel bowl standpipe,,, HAVE U BEEN HANGING OUT WILL GOOFY BILL ,,,,what's his name ,,, anyway yes or no is it good to do or not

Arisley · May 11, 2016

I don't remove the standpipe. I gutted it and replaced it, it still there. Well, actually, it was when the fuel bowl was there. I gutted the fuel bowl, it's long gone.

PSD POWER007 · May 15, 2016

What's the process in gutting the stand pipe?

Arisley · May 15, 2016

Remove it. It is held in with a couple of screws. Poke a screwdriver in the top and push all the guts out the bottom. Reinstall.

PSD POWER007 · May 16, 2016

Did you notice any pressure difference after?

Arisley · May 16, 2016

Not so much a difference, but it held the pressure better. It didn't drop off as fast. Still dropped off, at the time, I was running my 250/200's on stock fuel system. looking for everything I could to make the fuel flow better.

I now have a home brewed full fuel system. No more bowl.

PSD POWER007 · May 16, 2016

I'll have to give it a try at my next filter change.
I have the Strictly Diesel RR that keeps the fuel bowl and my stock pump keeps up pretty dang good. Gonna do a duel stock set up soon. Strictly told the the bowl would be fine with my size injectors. I'll do a bowl ****** if I ever go bigger.