injection pump tuning help needed
 

the truck is a 92d250. it has a uprgrade turbo and 2nd gen lift pump. been having ongoing issues for 2 years. swapped the injection pump 2 years ago and after enough tuning we were able to get it stop putting out white smoke. it ran ok but pretty sure there was a problem with it over fueling or something because sometimes it would go 70mph and sometimes it would struggle to go 60mph. when it was working good it would be sitting at about 20psi boost with your foot on the floor but when it acts up boost usually drops. we thought there was possibly something up with the pump so swapped it out for a NOS injection pump. now we are back to starting this crap all over but seem to be struggling with it more. yes we made sure to unlock the pump after installing it and pumped the lift pump to fill it before firing. we had to advance the old pump to get it to run decent so we did the same thing with the new pump. we had white smoke and and managed to get it tuned so the white smoke is gone but with the way we got it tuned right now it has no power. any time we adjust the power screw with the truck running it usually sounds good but when you shut the truck off it will not start back up. usually adjusting the star wheel some seems and the truck will usually fires up again but it seems like if you adjust it too far it won't start again. maybe this is a coincident but definitely not sure what to be looking at. any tips or advice would be appreciated. need to get this thing up and running properly again.

You have to use the low pressure piston pump, not the regular 2nd gen pump. Blows the seals out of the VE.
https://www.dieseltuff.com/product/1...93-ve-cummins/

i think that is the pump on there. i thought it was a 2ng gen fuel pump. there was a FASS fuel system on the truck when it was bought but we pulled all that crap to return it to stock since it wasn't needed and hung pretty low on a d250.

Ok, cool. That was my first thought.

2nd gen fuel pumps and the low pressure pump looks the same. Put a pressure gauge on it to verify.

Is the linkage adjusted to stock setting per the FSM, if it is not that will create all sorts of headaches

Do you have good fuel delivery to the VE? You will not make any boost, regardless of how big a turbo, if you do not have enough fuel to feed it.

Good luck, keep us posted.

the truck use to run good with the current lift pump that is on the engine with the original injection pump that was on the engine so i believe it should be the correct pump. we have not actually tested the pressure since i don't think pressure is the issue. if anything we are getting too much fuel which is why we were getting the white smoked. the original injection pump was removed because the studs vibrated loose and then we found the power screw casting broke but ran good even with it moving pretty freely with the loose injection pump mounting studs. also we currently have the throttle linkage disconnected so that it is not an issue

I thought white smoke was not enough fuel?

no white smoke is pretty much raw fuel coming out the exhaust.

Ask me what happens when you put 40 psi fuel pressure into a VE.

Edwin

Pull your fuel filter, dump it into a clean bucket and see what comes out.

i don't think the fuel filter is the issue but it is probably due to be serviced soon. we threw the original injection pump back on with a top that isn't broken and were able to get it running pretty good. definitely have power back but still getting white smoke occasionally. it we turn the power screw out 1 more turn from where it is in this video we were able to power through the white smoke and have it turn black. we have tried turning the star wheel up so that it can build more boost before being hit with the fuel but it didn't seem to make any difference. we were at least able to take it for a test cruise and it wasn't smoking too bad while cruising with 20psi of boost. it was able to do 70mph again but definitely seemed a bit happier doing it. we will likely be replacing the plenum gasket in hope that we will find and fix a small boost leak but the truck will likely be going in to the diesel shop that has done some work to this truck in the past to hopefully get it fine-tuned.

May want to bump the timing up a bit. My truck had some white smoke issues after pulling the pump for a rebuild years back. A little more timing fixed my white smoke at idle.

we have already advanced the timing and it doesn't smoke white at idle. it only start putting out smoke when you give it throttle like in the video i posted.

so truck ended up at the shop and apparently it was missing a valve on the return line. we think when the shop installed the fass fuel system years ago they removed it and when we removed the fass fuel system we didn't know about it and it seemed to run pretty good so we didn't worry about it. all is corrected now and the truck seems to be running real good.