TNutcher

It's not every time i jump on it all the way for awhile but this is the second time it has happened and it's pretty embarrassing.

First time was in pismo when pulling out a friends truck. Started creeping foreward then gaining momentum and started laying into it to get momentum going and get out of the soft stuff. It became unresponsive to my full throttle'd foot and began declining to like 3/4 or so throttle then when i eased out it died and left me stuck in a bad spot. I disconnected #1 and #3 injection lines and turned lift pump over to get fuel and after that it eventually started (5 minutes of cranking and ran fine)

Second time just happened. I was racing my friend (D-Max with an edge juice) and it did the same, started cutting out and de-fueling like around probably 50mph. f/p was near 7 egt's were... high boost was 35 or so and tranny didn't slip.

The first time my air filter was a little crumpled (had some sand splash up i figured) and i thought that was attributed to it was starved for air but didn't get how it took so long to crank over. The second time i had 1/4 of a take of fuel and could maybe see how with is sloshing around might get some air sucked in but it maintained more than 7 psi at the lowest. It's got 3/8ths line to the filter with the 150GPH FASS just pump by the tank. I don't get it. If someone has experience or tips on what to fix or what to do so that this doesn't happen please help me out. Thank you much I appreciate your time as it turned out a little long! haha sorry about the length.
Thanks again,
TNutcher

badme

My truck did the same thing. Right after the dealer put in a new VP44 under warranty, I fixed the problem. The problem was when the fuel was under 1/2 of a tank the fuel pump would suck air. The dealer insisted that it was my install of the external fuel pump. I put clear fuel line between the filter and vp44 and had loads of air bubbles. I moved the clear hose between the fuel pump and the tank, still air bubbles. Then I removed the sending unit and put it in a pail with just enough fuel to cover the pick-up screen and took a vaccume pump and pulled ( or tried to pull) a vaccume. All that I got was air, I continued adding fuel untill I got fuel instead of air. Bingo, there was a pin hole in the fuel line on the sending unit. Fuel preasure guage in the truck said 16lbs when it would fail. Those guages only know preasure and can not tell the difference between air and fuel.

badme

P.S. I also brought the sending unit to the dealer and showed them to prove them wrong.

JFlory

I just spent the better part of a week chasing this exact problem. The guy had the problem before bringing the truck in.
We put 100hp injectors, FASS HPFP, and new VP44 on a truck. It had a Comp. and Smarty. When we would lay into the throttle, then let out to shift(6 speed), the truck would die, or drop to about 400rpm then recover. If you turned the truck to stock, it wasn't as bad, but still there.
It was obviouse that air was getting into the line somewhere, and it had to be between the FASS and the tank or it would leak fuel.
We pulled the truck in and replaced the sending unit and put all new hose and filter from the FASS to the tank.
Problem solved.
Can't say that this is your problem, but it sounds simular.

JD

TNutcher

so would it be a faulty sending unit/draw tube in the tank or just something that comes "standard" with these trucks? Thank you for your replies
TNutcher

1-5-3-6-2-4

I think you're feeling the "big injector" syndrome........but It could be something else. BUT If you can restart it after cracking inj lines at the head. I'm pretty sure thats what you're doing. vapor locking between the injector and the injection pump.

I used to get it pretty often with the Jammer 5s now I can almost do it on demand with the DPP 250+ comps. can't let off the throttle too fast or the injectors draw out the fuel in the line faster than the injection pump can replenish at an idleing rate. Has nothing to do with the transfer pump. the injector is still dumping fuel out faster than the injection pump can fuel. in the instant that you let off the throttle after hard running. I chased this gohst for almost all of last year, until being satisfied on the Big Injector syndrome, I thought everything you have though of, sucking air...hole in the drawtube.....broke off suction when tank low.......Its the injectors.

TNutcher

I understand what your saying about the big injector syndrome and have experianced that when letting off too quick after a burnout or at the pulls but in these two cases i don't think it is the injector syndrome because it happens when I'm still in it full throttle. It starts cutting out and losing power before i let off and as i'm still in it full throttle. I have had the BIS but don't believe it to be the culprit this time, i think its' something else... Thank you for the reply though,
TNutcher

TNutcher

what would a vulcan draw straw accomplish and might this be the best choice for me if it is the sending unit leaking? Also is it supposed to have this condition or is it just wearing out? Thanks
TNutcher