2001 cummins surge/jump?
 

Ok new to the threads and new to the diesel world. Two days ago I went and purchased a 2001 24v CTD With a nv4500 5spd. It has a fass 150 new head gasket and ARP studs also has a smarty turned to 3. My question is what is going on. While driving md going between 1500 and 2000 rps the truck likes to run steady then jump a little but not hard. If I let off or punch it it stops. If I punch it, it doesnt hesitate to take off and I mean take off ... it flat out goes but I dont know what is causing this. Again it doesnt rev or hop hardly enough to register on the tach just very annoying. Any ideas?

It kinda sounds like a run away ....meaning your turbo is possibly leaking oil enough to get to your intake take the intake boot off the turbo and see if the is oil there its normal to have residue but it shouldnt be wet the other possibility is that you vp44 could be going bad and that is probably the most likely if you have the smarty tuner hook it up and run a trouble scan and see if its throwing codes let me know what you find ...

The only code it was throwing was for lift pump but I did some research and i found that could be from the aftermarket fass install... I will look at the turbo tomorrow but one thing I did find was some oil in my radiator but I think it might be from when the previous owner lost his head gasket and replaced it...possibly forgot to clean the system

Now that you say that check for air geting in the system also

May be a dumb question but how would I go about doing that

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Also I dont known if it has anything to do with it but ive got an oil leak...no idea where but its running down my bell housing and dripping there... Coming from drivers side a believe

Well my truck was leaking like a siv out of the push rod cover most likly place and the bigest thing is to make sure all fittings are tight ...when you lift pump failed how long did it run for after it failed

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It also could be the vp44 starting to go you could also take the inspection plate off the bell housing and useba flash light and see how much friction meterial you have on your clutch disc it i dought its the issue but iv have seen it befor

I found a fuel leak today on the number 6 crossover tube it was a bad boring installed a new tube and boring and I think it fixed the leak but didnt drive it to test the jump problem but I think that might have done it and I'm not sure about the pump it wasn't running when I bought it a few days ago

Well just so you know on 85% of cummins vp44 equiped trucks the thing that makes the vp fail is low pressure to the vp so the lift pump pressure was probably really low when it died and who knows how long it has been low but bellow 10 psi is not good the vp will start to get hot as the fuel cools the pump and bellow 5 psi fallure is pretty much going to happen to you have a fuel prussure gauge

Could also be a APPS. Same thing happened to my truck and come to find out it was the sensor, but I got lucky and just reset it and worked out

You can also volt check that it should have a sticker on the back of the sensor telling you what voltage it starts at it should be between .050v + - .005 range then it should go up as you move the throtle up for more info on that and diagrams go to bluechipdiesel.com trouble shooting it will give you pics and all