Thanks for your help. I am looking into the vp 44 as suggested. In my area there are no diesel mechanics that work on light trucks, do you recommend taking it to a dealer to be diagnosed for sure? Also, what is the likelyhood that the problem could be the APPS? What is the normal cause of a VP44 failure, would my chip have caused this?

 

The VP44 is notorious for dying between 40 and 140K miles. The newer ones have better electronics and a few smaller updates that make them a bit more reliable. It is claimed that low fuel pressure causes them to die quickly. There is a lift pump that feeds the VP44, the lift pump is cheap and way underrated so when the lift pump dies, the VP overheats and works extra hard to pull fuel from the tank and then pressurize it to several thousand psi. Do a search on lift pumps and you will find many options from 100 to 700 dollars on lift pump solutions that will help preserve the pricey VP. However, when all is said and done, VP's still die with enough miles, they are the weak link on 24V cummins. The cheapest route is to buy a Holley Blue Electric aftermarket pump and have it feed your current setup... it acts as a booster pump of sorts to ensure adequate pressure is always present ie 8 to 15 psi. If you have a little deeper pockets, get a Fass system, it will eliminate the stock lift pump system entirely complete with better fuel filtration, better pressure and more reliability. I'll bet that your lift pump took a dump a while ago and so your VP is slowly dieing. I wouldn't let the dealership touch my truck unless it was free warantee work.