Hi,
I am no mechanic, but have of recent decided to start learning and start working on my own stuff. I say this so if you answer you do not assume I understand acronyms or anything else for that matter.

I have a 1993 F250 with the International 7.3L idi engine non turbo charged.
A bit of background to the problem I am posting about.
I recently had the sending units changed out because the fuel gauges did not work. Prior to that happening by about a month, the truck started starting hard. After I had the sending units replaced it really began starting hard especially if it sat over night.

Recently got the time and started trying to debug and do some maintenance at the same time. so far I have done the following with the help of a mechanic buddy. My friend recently had a bad heart attack so I am on my own again.

Replaced the return lines (they were leaking)
Replaced the glow plugs and the glow plug relay
Replaced the injectors (two were leaking)
Rebuilt the filter pump housing
Replaced the lift pump.

As a result of all the hard starting I replaced the starter too.

Absolutely no difference in starting. It will restart pretty good if it has only sat for a few hours, but if it has sat all night I can count on running the batteries flat, charging and finally getting it going on the first recharge if done within an hour or so.

Once it is running it runs really well and stays running smoothly.

Could this be a partially clogged fuel line? It and the injector pump are just about the only things I have not replaced. Could it be sourced in an improperly installed sending unit?

Would switching over to an electric fuel pump end this pain in the butt? I have seen that quite a number of folks have done this.

 

If you haven't already replace the fuel filter.
It sounds lik eyou are getting air in the fuel filter.
This is a common problem. It will run fine until it sits over night.
next time you try to start it, crank it for a few seconds and then go to the fuel filter and press the Shraeder valve ( bicycle tire ). See if fuel, or air comes out.
If you get air that confirms that air intrusion is the problem.
Repeat this 4- 5 times until nothing but fuel comes out.
Then try to start it with a full g.p. cycle

You said you replaced the fuel return lines.
Did you also replace the plastic injector caps they connect to?
And more important, the two O-rings under the cap?
These are known to shrink and allow air in.

 

There are two fixes that are important here:
1. The return line on the fuel filter head needs to be blocked off. There is a Ford TSB on doing this to solve air intrusion issues. Problem is is that port originally had a check-valve inside, but that has now disintegrated.
2. Old lift pumps can leak; if you've got a leaking lift pump, replace it. It's cheap, and then you don't have to worry about leaking diesel into the engine or it failing randomly.
3. If you still have trouble, replace the line from the lift pump to the fuel filter head with a piece of rubber hose and a squeeze-bulb primer. A primer bulb like this has check-valves internally and will keep the system primed better than anything else. Plus, it makes life easier if you run out of fuel.
You can easily make this mod using a tubing cutter(any hardware store, used for cutting copper tubing) and a bit of 3/8" rubber hose.

 

What brand glow plugs did you use when you replaced them?

 

I just picked up a truck a couple weeknds ago the previous owner couldnt get to run. HE replaced the mechnical pump, put clear line in at IP, filter, before mechincal pump etc. I showed up with a 5 gallon diesel can and electric pump, got it started in 20 seconds with practically dead batteries, then trailered it home. Finally got around to messing with the truck this week, just running a rubber line directly to the top of the fuel sending unit with an electric pump to elminate fsv, lines, and mechicanl pump. Still found air seeping in even with a full tank. I got under there and felt and listened all around and found the elbow on the top of the sending unit actually had a pin hole. i mixed some quick steel putty and shaped it around the elbow, all air went away at filter head, truck started up with 10 seconds of cranking and ran perfect for the next hour.

I'd check your sending unit, you will only be able to find a leak with an electric pump though since the mechanical doesnt pull a constant vacuum. Or you could just quick steel the whole fitting to be sure.

 

I just installed an electric pump and filter setup myself to get rid of that giant filter and bracket right in the way of the turbo inlet on the engine.

 

the fuel heater on the top of the stock fuel filter housing, it can leak air into fuel filter housing.

 

Hey Shawn how much modification did you have to do to put that on I just have a cheap faccet electric fuel pump and it does the job but that pump looks awesome and what year an model is it on?

 

Well i did alot of modifications at the same time lol. The pump you can just mount where your facet is, but its a 5 micron filter in it, so its going to filter finer than the stock filter so it becomes useless and unnecessary. I had ESCO make me a braided stainless jic 5 line and they supplied thos fittings, plus a tee and barb fitting for the top of the pump. I then installed a 5psi swaglock poppet valve to act as an air vent, but will only vent pressure at 5psi so it keeps the pump charged with fuel pressure. ESCO charged me around $100 for the 5ft line and all jic 5 fittings. the swagelok poppet was $13.



you can see the fittings and poppet valve in these pictures, plus the extra room you have to run an intake pipe straight into the turbo

Edit it's a 1993 F350, 7.3l factory turbo

 

Where and how much did you get your whole setup?

 

He hasn`t been on since 12/18. Might want to click on his user name, and then
send him an e-mail from the drop down box.

Charlie