99 3500 RAM 5.9 DIESEL. Won't run now. Was hard starting so I used
additive for fuel 1st time at 230,000 miles. I changed the filter and it started
great for a few days. Again wouldn't start and used starting fluid and it started. but didn't sound quite right and I shut it down. Decided after much bleeding to rechange fuel filter no help. Only start with starting fluid, but no trottle respond. Ordered a new lift pump and intalled it twice to make sure.
Still acting the same, if chanked longer then good it attempts to run just as switch is turned off. Need some good sugggestion.

 

VP44 or apps

 

Your VP has died in all likely hood.

 

Lift pump not running properly, loose connector, ran wire direct and pump
running. Truck starts but no trottle and only on a few cylinders. Getting
fuel front of engine 1,2, 4 and 5.
Runs badly, no fuel on 3 when line cracked. Haven't open # 6 due to location.
Exhaust has good pressure comimg out,(not plugged).
Could VP44 bw dead if fuel is bleeding when injectors are open.
still open for suggestion Wayne

 

Yes. Computer and mechanical. One or both parts can fail and still get some fuel flow but no power. Someone else with more experience might know something else but if lift pump was having issues that can cause the the VP to die and some times rather quickly. With that many miles consider your self lucky.