Hey ya'll. I'm new here, and I'm really struggling with the 91 F250 (IDI) I bought a few months ago. I could really use some help.

Here's the quick and dirty history.

1. Previous owner did not use it much in two years he had it. Used ether to start it when he did. Instructed (dumb newbie) me to do the same, which I did until I knew better.
2. I had a Ford mechanic put in all new glow plugs, a new controller, and a new wiring harness. Now truck would start without the either and then die. Several long cranks would usually get it started eventually. If it sat for more than a couple hours, the whole process would repeat. As I understand it, this is classic air in the fuel line symptom.
3. Next step was to order a new injector return line kit, which I installed myself. I have never worked on a vehicle before, but I figure I have to learn some time. The installation was a pain, but seemed to go fairly well. Several of the injectors were wet with fuel before, now they are 99% dry.
4. Unfortunately, this not only did not fix the problem, it seems to have made it worse. Truck will sometimes stay on longer during that brief, initial fire-up but seems to require more and longer cranks to get it going. Worried about my starter. Today I tried 4 long cranks and coughed to life each time only to die again. This is new behavior.
5. Two options for my next move: replace the whole fuel filter assembly (see *below) or replace the lift pump. Any advice on which is more likely to help?

Random Notes/Symptoms.

1. * There seems to be fuel leaking from the water separator bowl. I can put my finger beneath that thing and come away pretty wet. Also, the plastic dohicky that holds the water drain hose on is extremely flimsy.
2. I can't see anything leaking from the fuel filter heater element that apparently is prone to leaking.
3. When it does start, the engine idles high and roughly for about 5-10 min. before it settles down. Probably unrelated, but maybe not?
4. Batteries were relatively new when I bought the truck, but I feel like I'm beating the hell out of them with each start up.

Please help.

 

If the fuel lines are wet anywhere, air can get in. When you replaced the return lines did you lube the o-rings and caps with vasoline or oil or something? The o-rings need lubed or they can tear and they will let air in. You can get an one piece filter that eliminates the bottom cap on the fuel filter. Chasing air intrusion can be flusterating. Quiet a few members have installed an electric fuel pump to save the starter. The e pump doesn't cure the air intrusion, but running the e pump to recharge the fuel system stops a lot of cranking on the starter.

 

That fuel leak on your filter may not be your only problem, but it will for sure cause what you are describing.
the running rough after it does decide to stay running is the same problem, it is just working the air out of the system.

 

Thanks for the replies guys. Appreciated. I did lube up the o-rings, but by the way everyone is emphasizing it, I may not have used enough. Does anyone know of a step-by-step thread for installing an e-pump? I'm pretty new at this

Thanks and happy thanksgiving.

 

I would change the fuel filter, there are versions that eliminate the plastic cap on the bottom. Next, after it's ran but sat a few hours, take the fuel filter off and see if it's right full, or only partially. If it's partial, you still have an air leak. A nicked o-ring, a screw type hose clamp used instead of a spring clamp, or an old hose somewhere can all be culprits.

 

If you want to install an e pump it's easy put it as close to the tank as you desire (e-pumps push better than pull) mine is under the hood and seems to do alright... most members put there's right after the tank selector valve then all you have to do is cut the line and install the pump... Make sure its the rubber line (personally if you put it there I would put new fuel line in. Make sure it's for diesels) then after putting it in place and making sure you have a good ground give it power either from the key or from a toggle switch

 

Forgot to mention make sure it's not above 7 psi for the e-pump or you can blow out seals in the injection pump

 

Ordered a new fuel filter bowl from dieselmann and finally had a chance to install it yesterday, along with a new filter and a new olive for the hard line from the filter to the injection pump. Primed the truck and it fired right up, but the real test was this morning, after it had sat.

Happy to say I have "fixed" my first vehicle!