Hello everyone,

I picked up a 93 F-350 4x4 with a 7.3l non-turbo and a auto with just under 300k miles. I got this for a smoken deal (bought the plow and got the truck for free more or less) from the guy I plow snow for to start my own snow plowing company this next year and just to have a good work truck around. For the past two years this has been my truck to use for plowing and has been taken care of. Needs a little tlc but nothing to major, just needs brakes, u-joints ect nothing to big. I also plan to take the box off and build a dump bed for it, fix the little rust there is on the cab and a fresh paint job.

The problem it is having is that over the past few months is takes a bit more to start it and runs rough then it clears up and runs great then runs rough again, back and forth with no rhyme or reason and progressively getting worse. When it runs great it has more then enough power to push or pull anything I want it to.

So far the fuel filter has been changed twice with no change. I took it to a local diesel shop and had a guy listen to it he though that ether there is something wrong with the IP or it is sucking air in the fuel line some were causing it to run like that. I am wondering were do I look first at it sucking air as far as I can tell there is no fuel leaks. Any thought or ideas, trying to do this on a budget and I dont have the cash right now to get the pump worked on and hoping it is something simple to start with. I am new to 7.3l diesels, been a Chevy guy most of my life but have owned a few Dodges and Fords. Thanks in advance.

 

Air intrusion can cause that problem. It's hard to find though because it usually lets air in while letting hardly any fuel out. The easiest things to check are the small section of rubber fuel line that connects the hard line from the frame to the fuel pump as well as the hard line itself as the frame tends to rub holes in it. Also check to make sure your return lines are dry as these tend to leak as well.

 

I changed the feed line from the tank switch to the Lift Pump, now its not an issue , also might think about a priming pump or deleting the LP, and going electric..

these IP's like about 10 psi from a pump .... keep us posted