I would like some help if you guys have any ideas. The other night I was runninng down the freeway cruise set at 67mph suddenly there was a funny thumpfff sound the truck slowed right down when I looked in the rear veiw there was grey smoke and it was running real rough pulled over shut off looked over everything all looks ok started back up no power running rough oil presure ok temp also ok shut back down got wrecker tow to shop now will not start. any ideas???

 

Injection pump....

 

Sorry, Injection pump selinoid....can't type or spell today.

 

Sounds fuel related to me. I'd make sure you didn't hit something in the road that flipped up and cut a line or something. Did you notice any spilliage on the side of the road? I guess if you did, you'd know right off. I'd check fuel and air supply. Sorry I can't help more.

 

Sounds like the injection pump but let us now when you get a chance to get it in the shop.

 

Several things come to mind. Without a fuel pressure reading we can only guess. First, I doubt the inj pump is bad, it is a P7100 and they have relitively few problems. The things to look for are, 1 lift pump, 2 overflow valve, 3 Inj timing, 4 air leak in fuel supply line, 5 fuel level in tank, 6 pick up tube in tank. If you can rig up a guage to get the fuel pressure you can save a lot of time and money finding the problem and get back on the road.

 

Turbo boot came loose?

 

Turbo boot or intercooler boot

 

Another good reason to have gauges in your truck... Fuel Or Boost gauges would of shown either problem...

 

Yes, but the truck will start and idle fine with a blown boot or boost leak.....I agree with Hemi Cat - it is doubtful that there is an internal problem with the P7100. Most likely, the P7100 isn't seeing any fuel. An inspection of the lift pump and overflow valve would be a good place to start......and, of course, a fuel pressure gauge would really cut down the time it takes to find the problem.

 

Thanks for the replies sorry it took so long to get back to you guys I haven't had any luck figuring this out yet, it seems to have fuel enough to the injection pump but has not been presure checked very little presure at injectors I need to find a good mechanic the guy who was checking it out doesn't have the equipment or knowledge to do the job Do any of you know of one in central Michigan

 

My brother said he is willing to help if you still need it. He is not mister know it all, but is a heavy truck mechanic. He lives near Owosso, but has no problem going your way. If interested let me know how to contact you.

Paul

 

id say lift pump or fuel supply has a hole in it check fuel pressure between lift pump and injector pump if no pressure there go to tank lines fill up tank all the way to the cap might spot a prob

 

well it appears to be lift pump only 3 to 5 psi at injection pump with clean filters and all else looks good new pump on its way

 

Sorry I didn't keep you guys up to date but here goes well it wasn't the lift pump like I thought or the over flow valve, the pressure wasn't being checked correctly took the truck to local cummins shop presure checked out o.k. they couldn't time it said it was injection pump so they removed and sent in checked out with nothing wrong so put inj.pump back on still could not time discover crank gear had slip 3/4" so tomorow they put on new crank gear, key and front seal