started my truck today warmed up ran for at least ten min. unplugged heater started to remove plow. truck shut off.

acted like pmd but ive been running the same one for almost two years in front of the rad in the grill been fine. lately ive noticed some hickups like stumbles didn't know if it was just some water in the fuel every once in awhile ill be at a stop withmy foot on the brake and it revs up and wants to lunge. I don't double foot were I do it. its possessed I guess.

back to today tried brand new pmd ive had for a backup just incase new stanadyne grey pmd. it fired up shut off. figured fuel shut off solenoid. un plugged, started engine rough idle plugged in smooth. unplugged what I belive is the optical sensor on top of the injection pump starts and dies. engine doesn't attempt to start now. I checked the t valve and turned engine over sprayed fuel solid stream to the pass inner fender im sure that's plenty. checked fuel flow from fuel bowl to pump. I have what the previous owner said was feed the beast fuel line. I don't know if its worth a **** or not but I have one. turned engine over intake vally has fuel now so im thinking that's good. I have another ds4 injection pump from the pic a part casted 00 im thinking 2000 probly doesn't have the miles mine has I think its out of a van if I remember correctly. I about ready to swap them out its snowing like crazy here in indy. and I need the truck back what do you guys think??????

my truck 1996 chevy K3500 6.5 223,000 miles 4L80E

oh new oil pressure switch and lift pump 2yrs ago if any one asks

 

Do you have a clear hose on the return fuel line from IP? this can rule out if you are sucking air I did a ton of work on mine New everything. The problem ended up being the sock on fuel line inside tank.

 

Well im at a loss wouldn't start last night. This morning I didn't feel like changing the injection pump in 6 inches of snow and cold. my caring side let go I unplugged the glow plug solenoid looking thing. no glow plugs shot either down the intake runners and now its running. been running most of the day stumbled a bit like it was missing got it back home running okay. just changed the fuel filter see what happens. forgot to mention i unscrewed the fuel shut off solenoid and plugged it in to make sure I had power to the pump and to make sure the solenoid worked well it does. its possessed. weird part I loosened the #1 injector line to see if I could get fuel before it started. no fuel. idk why the starting fluid made things work. started truck after an hour it started on its own with no gogo juice.

 

Don't use gogo juice (ether). It may not have caused problems this time (luckily) but it is destined to in the future. The injection lines may have been vapor locked, which can easily be fixed by loosening injector lines at the injectors one at a time until fuel squirts or dribbles out, then tightened.

 

cviola is correct about the use of ether it only takes one time and bang if you feel the need to aid starting use non-stick cooking spray it works without causing catastrophic damage to the engine

 

Good point mayhem, Although I haven't heard of using non-stick cooking spray, I have however, heard to use an "oily" alternative to ether.

 

There is a clue i9n what you have already done-Your shut off solenoid appears to work.

You have not mentioned any codes-get them checked out for free at you auto prts store and write down just the code #'s,the definitions their code reader will give will almost certainly be wrong.
Post the codes here and we can provide the correct definitions.

Now to what you have already found out.

When the OS was unplugged and the truck quit,was a real clue-it should still run and start on the CPS only and it's not.

CPS fail and MUST ONLY be replaced with AC Delco CPS-aftermarket sensors are often bad right out of the box.

Another thing that requires attention is to look for and remove the OS electronic noise filter if it is still present-unplug the filter and plug the remaining harness directly into the OS.

Let us kniow if that helps.

Also with reguard to the surging-do as directed with the clear return line from the IP and monitor for bubbles-you may have an air leak pre lift pump?

But get us the codes the truck has for sure.