u.s mma

I rarely take my truck wot to start with. After the gds install I gave the fuel screw another turn, a week or so later i got the snow controller mounted, I was right at 31psi when i mashed on it. Well I was driving the other day in traffic and stomped on it, could only get 28. Today, pulling onto the highway, only 28. with water, no meth. What should I look for? lift pump maybe? I don't have a fuel pressure gauge either.

Jim Lane

Boost is also dependant on the load on the engine; did you try it under the same scenario? Same weight, same grade road also check for any leaks on the outlet side.

When I installed mine I went from 28 PSI to 56 PSI and I am back to around 1 turn past where I started with the fuel screw and I am still baffled I want to feed it.
Jim

wannadiesel

Outside air temp has a lot to do with boost too. Cooler = more boost.

Bob Beauchaine

You didn't by chance advance the timming? That can also lower boost.

Bob

u.s mma

Mr. Lane, yes I was driving through the same area, unloaded.
Wanna, you might have hit the nail on the head, it was in the 70's yesterday while I was out driving, probally in the 40's or low 50's before.
Mr. Beauchaine I have not messed with timing as there are times this truck is worked very hard and from what I have read on here the timing is more for just play trucks.

PapeCAT

WOT at higher RPMs = more boost as well... well if you have the 3200 GSK. So were you WOTing it at the same RPM as before. You say you don't usually WOT it? I w0t mine all the time for short blasts.

u.s mma

Papecat, I was racing around for a while after the 60 wheel and with the snow kit, but I was going through methanol real quick, and my mileage suffers something fierce. My truck is not exactly light. I don't have a tach, thats a good point about the power band. Ill take her out this afternoon and open it up. Im kind of a hypochondriac, and this truck is supposed to take me to fairbanks in a month so it got me kind of worried.

Crossy's son

your still running a stock lift pump? I'd get a Piston LP soon. with your mods your probably pulling the fuel psi to 0 now

u.s mma

yah, i was thinking that. i need to do some research on the piston pump, i don't have any idea what is involved or price.

peobryant

A piston lift pump will make a world of difference. I highly recommend it.

Crossy's son

you'll need the pump, the spacer, cut the insulation on the block, and make a new line running to the pump or buy it from cummins.

rollincoal23

the piston pump makes a pretty big difference in the top end. it lets ypu fuel all the way to the top of your RPM's