I have a 93 cummins....driving down the road one day at about 60 miles per hour truck started losing power and blowing some white smoke,then cleared up.Went into the store and came back out and truck would not start,popped the hood and primied the lift pump and released the valve on the fuel filter a lil bit,truck fired right back up and ran fine that nite and the next day. Left my house later that nite and dint even make it half a mile,started idiling real rough and pouring white smoke out,pulled over and put it in park,had to have the accelerator all the way to the floor to keep it running,very rough idling too. Opened the valve on the fuel filter and had a ton of air in it. Finally babied it back to the house,changed the fuel filter and put on a brand new lift pump. It is still doing the same thing,pouring out whitish/gray smoke and you have to hold the accelerator to the floor to even keep it running.


People have told me that once the lift pump goes out it wipes out the injection pump so i am desperate to try any other ideas before i go and spend the money on a new injection pump

any help is greatly appreciated and i want to thank you in advance for taking the time to listen to my troubles

 

I think it's more likely that you have a cracked fuel line between the tank and the lift pump.

 

most likely. probably sucking in air.

 

okay...im gonna try that in the morning.....will the injectors need bled now? And what is the correct way of doing that if it needs done?

 

You have air getting in to your fuel lines somewhere...ill put money on it.

 

If you indeed have to replace your fuel lines or during diagnosis your lines get drained, yes you should/will have to bleed your injector lines. Im not familiar with first gens, but the proper way i was taught to bleed air out of fuel systems in diesels is first you need to get the fuel to the pump via pulling the supply line off the pump or bleeder screw open while running the LP. Once you have fuel at the pump, you can start by bleeding your lines. How I always do it is first crack all six lines at the injectors, while lines are cracked, have someone start cranking the engine. Watch for fuel at each injector, as you see a steady flow of fuel come out the lines, tighten up that fuel line while the engine is still cranking. As you do each line, the engine will seem like its going to fire, just keep cranking it over and tightening the lines as you see the fuel flow, once the last line is done, it should run perfect.

 

I want to thank everyone for their advice and help!

I had an auxillary fuel pump (holley blue) on the truck that has been gradually getting worse,well i by passed it temporarily today and the truck fired up on the first crank and seems to run fine now