We finally got this truck up and running but have a couple more issues.
to recap what was done...new VP, Fass and RV injectors as well as new Pump gear.
Put it all back together and it fired up no problem.
Every now and then the Fass pump does not start...no noise. Turn key off and on again...pump starts.
If the truck sits for even an hour...hard start and white smoke. Checked oil in crank last night...diluted...smells like fuel. No external leaks. Maybe a bad injector leaking down?
HG?
Also, truck has an Edge Juice, changed nothing on it and now have no boost signal from MAPS to display...reads ' 0 '. Checked and rechecked connections.
No CEL.
The fass is putting out 19-23 psi and hops around alot on the display. Isn't the pop off on VP trucks right at 23 psi?

Any help is appreciated.

Scotty

 

I'm not sure what you mean by pop off. 19-23 psi is too much--you want about 12-15. The VP44 acts like you describe (hard start) with excessively high input pressure.

I know that there are cases of people running high lift pump pressure like that and having no problems, but they're the exception, not the rule. First thing I'd do is change out the FASS spring to drop the pressure and see what happens.

Mike

 

I'd be concerned about an injector problem, considering the oil level is rising and you're getting white smoke. Classic signs of unburnt fuel in the cylinder. If you mean pop-off of the injectors, I think VPs are 23,000 PSI. Is it possible you mixed up the numbers there?
Midnite is right about the high pressure to the VP44. this can cause problem sometimes, I have heard, but I have the FASS getting crazy enough on my 99 that it broke the FP gauge and I have not had any problems with starting mine. This is easy enough to overcome though, just wait until the FASS cuts off, after turning the key on, and the pressure to come down. before actually trying to start it. This usually occurs anyway, if you obey the wait-to-start light.
The computer controls when the FASS runs, if you have it wired to the factory lift pump wiring for the trigger, as I do. The FASS will come on when you first turn on the key, then it will not run again until the truck has started. This is something most of us pay no attention to until we are trying to get a truck running. Once you turn the key off, if you wait about 2-3 minutes before you turn the key on again, the pump will run when you turn the key on again.

Chris

 

I thought there was a pop off for the return line on the VP...? no? I thought I remembered that if the pressure was too high it would send fuel back to the tank. Is there no relief valve? It seems like the truck gets good pressure and then it dumps back and forth, causing the erratic fuel pressure readings. I should also add that when I pulled the old injectors there was fuel at #2 cyl and that injector was soaked in fuel. Even when I pulled the valve cover, I could smell fuel. cracked head maybe? Going to check the connector tubes too.
The readings for fuel pressure are coming from an Attitude. I prefer mechanical. Its not my truck but its sure giving off some problems...one after another after another.

More when I get to it. Back to work tomorrow so might not knwo for a few days.

Scotty

 

I have never heard of a pop-off valve on the VP44 fuel supply circuit. The reason the FP gauge jumps around, as I understand it, is because of the VP44 itself, as the solenoid inside cycles.
I'd carefully inspect the number 2 injector body to see if there are any cracks. I had one crack length-wise up the side once, and while it did not cause white smoke, it choked out some serious black smoke at engine speeds that would not spool the turbos.

Chris

Chris