How long since you have repaired the fuel line?

That is possibly air causing your problems, or a dieing fuel pump.

 

Sounds like air to me. Or you're getting an intermittent connection on your shut off solenoid. That's about all I got.

 

Do I need to purge the system of air or will it work it self out as it runs ( I did the lines the same day it died)

 

If the lift pump is working properly the air should pass. If you have a model 80 filter, square fire wall mounted box, there is a air bleed at the top.

With the engine running, open the fitting slowly and fuel should be pumped out along with any residual air in the filter assembly. I would also put a piece of line off that fitting and put into a container so you won't be spraying fuel all over the place.

There is also a water drain on the bottom of the M80 but we can deal with that later.

 

And cause I have forgotten twice already...

Welcome to Diesel Place !!!

 

Does it surge and die or just die like you turned the key? Any odd acceleration/deceleration just before it happens?

 

We need some more info about it dying. You say you replaced the "fuel pump" Just to confirm you are referring to the mechanical pump on the passenger front of the block?

 

The fuel pump that was replaced was the one on the side of the block, the fuel lines have been replaced as well as the fuel lines going to the injectors. We found a fuel leak on the filter due to the WIF being cracked, we fixed that and it is no longer leaking now. There are times when driving it that the idle gets very uneven and it acts like it is trying to stay running. The latest symptom it is having is when I hit the gas pedal to get it to go over 50 miles per hour it accelerated but then all of a sudden it lost speed and the truck stayed running during this it just lost speed and then it would recover a bit it did end up dying but I was able to start it pretty quick and it kept going.

 

Sounds like fuel restriction or air. Start small by installing a clear line off the injection pump return. Take the fuel cap off and sell if it runs better. Possibly Rusted fsu? Stopped up sock? If no air and pull the cap doesnt help I would double or triple dose the fuel with some diesel fuel treatment. Maybe throw some 2 cycle in it? Dont go buy in injection pumps whatever you do:HiHi:

 

Sounds like fuel restriction or air. Start small by installing a clear line off the injection pump return.

I think its sounds more like a restriction or starvation.

Do the clear line on the IP as suggested. Cheapest best diagnosing there is. Where is Bobs picture? :idea:

 

air....

 

air

 

Ya it's a tied between air leak or a pump that's working intermittently.


I would pressurize the fuel system and look for leaks. Separate the return line off the IP and plug the IP side and put 5 - 10 psi TOPS to the return line. More than this and you be popping seals and all sorts of other "fun".... This will pressurize the whole system and you can go crawling around looking for fuel poring out. Also keep an eye on the engine oil level as it could be pumping fuel into the crank case.


http://www.dieselplace.com/forum/63...582-how-remove-air-fuel-system-find-air-fuel-leak-6-2l.html?highlight=bleed+air


Post #21 for a down and dirty cheep tool to do this a different way.


If you don't find any leaks, which could be the pickup in the tank also, I would tie in a pressure gauge to the fuel line after the pump and see if have any.

 

One thing to check would be whether they used the correct lift pump. A SBC (350 gasser) pump will seem to fit, but the actuator arm is different and it won't pump enough volume (so I have heard).