Connect it to the test port in this picture and you'll be reading your post-filter pressure.
It's an 1/8" NPT fitting.

 

the code that we got was 1689? manufacterer control. auxiliary inputs. auxillary outputs. that make any sense? any alternative to a vp44 if i have to buy a new one?

 

P1689 (M) No Communication Between ECM
and Injection Pump Module:

Data link circuit failure between ECM and fuel injection
pump. Low power, engine derated, or engine stops.

Connections?

 

If you're reeeeal lucky, maybe connections.

Most likely, toasted Injection Pump electronics.

 

IMHO Your lift pump is gone. Hopefully it did not take out your vp44. Mine did the same thing. If you bump the starter and you here the lift pump humming kinda loudly and for a long time it is no good. It should build pressure and shut off pretty quick...like less than 2 seconds. Mine would run and run and run but never even be able to fill the filter back up. Good luck

 

luvturbowine! yes its running and running, long after i shut off the key. i think that is part of the reason my battery is so dead. that and trying to start the blasted truck! i have a diesel guy picking it up tonight and hopefully thats what he will find! thanks

 

okay guys i really need some help now???? i repalced the lift pump due to when i checked it it only had 5-8 psi, now since the truck doesnt start yet i have to bump the starter then let the pump run its duration and check pressure. as soon as the the pump stops it losses all pressure??? the new pump is putting out around 17 psi but eh truck still wont start. is there something that i need to do to prime the system? i had to blow air in reverse just before the lift pump back to the tank to get things flowing again but i dont understand why the truck is still dead. i hope its not the vp44 is there any way i can test this thing?

 

Crack the line at the injection pump while the lift pump is running when you see fuel coming out tighten the line and try to start the truck.

 

the lift pump should lose pressure after pump stops, a injector line at the head and see if fuel is getting up there,sounds more and more like the ..vp 44
R.I.P.

 

Loosen injects 1,3,4 and crank on it till it leaks fuel from these or starts. Then tighten them up again. For safety shut it down while you tighten the injectors back up.

If this doesn't work then the VP44 is done... But since you only had 5-7 PSI of fuel pressure I would highly bet you toasted your VP44. Anything under 8 PSI is trouble for your VP44...

Time to install a set of guages... (Fuel Pressure, Pyro, Boost)

Also Time to get a new VP44 pump... NOT CHEAP!
The fuel pressure guage could of informed you that the LP was dieing and allowed you to change it before you cause any damage to your VP44...