Recently I swapped in a set of 43LB injectors and removed the Procharger FMU. Last night I noticed the fuel pressure drops from 60lbs to about 50 just before the truck shifts (1-2 @ WOT) and then it jumps right back up to 60, then at the 2-3 shift it does it again. I am using the inline aux pump that comes with the Procharger kit and the stock pump in the tank. Do I not have enough pump? Or is it maybe the fuel pressure regulator? Or is it normal?

 

TTT

Anybody?

 

definately not normal.

there are a few things that could be your problem, you dont want to see that fp drop ever.

most likly you are super rich, so rich that you are using more fuel than the pump can supply. have you tuned the truck? if your a/f ratio is correct then you have a fuel system problem. could be your filter, or one of the pumps or perhaps thats aux inline isn't that good of a pump. i am sure a walbro gss340m pump would handle what you are doing. i ran one up to 10psi and a 100shot on a 6.0 and it didn't run out yet.

now that i think of it the stock pump ran out about 9-10psi, maybe your inline isn't running at all.

1. check your tune
2. check to be sure the inline is running
3. try the filter, cheap and easy
4. stick a known inline pump in there, the gss340m.
5. hmm, i am sure it will be fixed by the time you get to 5. :-)

 

Changed the filter this morning. It was definetely restricted but it did not help. I am leaning toward the fuel pump now. The pressure stays at 60 at anything but WOT and then only right before the shifts and when it drops it fluctuates a little between 50-52psi and then jumps right back to 60 when the truck shifts. What's the one that goes in the tank and replaces the stocker? That's the one I want, are they plug and play.

 

my truck does the same thing. did we ever come up with an answer to this problem?

 

What Size wire are you guys running to the External pump
i would go with very large wire like 10guage
And make sure the Ground is nice and clean and thick aswell
I was able to make over 500rwhp with the stock ATI inline pump

 

Mine truck does the same thing, but not all the time. my fuel pressure at idle is getting worst, which is down to 44#. We just got a 03 with a bad pump so i'm gonna try to keep the module and put the walbro I already have in it. That way if I screw up the module I'll still have my stock one.

 

I replaced the pump with a Walbro GSL392 inline. No Problems since. I reused all the wiring, hose and mounting hardware from the ATI pump, and used hose barb fittings and clamps to plumb it in where the ATI was.

 

I want to try an inline fuel pump but can't get a straight answer on what else I need to purchase for the hookup. I know I need some sort of relay, harness, and fittings.