I have a 94 f350 turbo diesel, its the older style. 106k miles and 99% of the time this truck runs like a champ! Recently, it has started dying after running for a few min and then take a while to start back up, and as of today instead of shutting off it seems to go into this limp mode where it runs really rough for a min, the engine light comes on and then after about a minute it clears up and runs fine again...I can figure most things out but when it comes to possible electrical things..im pretty much lost. my first guess was a fuel pump but then I read that maybe its all the o rings and stuff in the fuel lines and then I got confused! it doesn't blow any smoke, this problem only lasts a minute or two and then it will run just fine. any help on where to possibly start would be much appreciated. id like to try and figure it out before having to spend who knows how much for a shop to mess with it. its a very clean truck and very well maintained. im not sure if there is a solenoid somewhere, the fuel pump, injector or if I should start replacing fuel lines hoping to fix an air leak somewhere....

 

Sounds like the usual air intrusion issue. Basically the fuel system is supposed to be a sealed system. Once the o-rings wear out they allow air into the system which allows fuel to drain back to the lowest place in the system (tank) leaving you with just the fuel thats stuck in the injectors/lines. When you start up, the engine uses all that fuel then runs out and you have to crank it over for a minute or two to pump fuel back up to the top end. Then it'll start though it may be a little bit rough as the fuel pressure is low initially. To fix the problem you can either overhaul the fuel lines and replace all the o-rings (technically the right way to go) or you can replace the mechanical fuel pump with an electrical model then run it for a few seconds before you start the truck to bring fuel back up to the top end.

I recommend the latter. Its easier in every way and you simply don't have to deal with the mechanical pump. When I had the issue it was so bad that by the time I had pumped the fuel back up to the top of the engine the batteries were too low to start it and I had to charge them before I could drive the truck. Fuel pump on a toggle switch or hooked into a power-on-ignition voltage source takes care of all that mess.