ok,use the process of elimination,gut the shut of valve,why, when engine starts on eather voltage goes higher and holds shut off valve open,if that is not the the problem hook up a 5 gal tank to lift pump,elimanates fuel lines ,tank,ect. lots of good information on this board also lots of dogs chasing there tails. eather is only bad when when people overuse it.

 

OK, I hope this helps somebody.
Last night I tried having a friend shoot some air into the fuel tank while I looked for leaks and found nothing.
This morning I checked every fastener I could find. Found that the 10mm bolts on the injector "fuel return lines" were not real tight. Some took a 1/4 turn, several required almost a half turn for a good snug. Found no other loose connections.
I took the push on connector to the lift pump off. Cleaned it out with WD-40 and air and applied a liberal dose of grease to the male end of the connector and pushed it back on.
took the air intake off the turbo - squirted a bunch of WD-40 into the intake hose and a few squirts into the turbo and put the hose back on.
The engine fired on the second spin and smoothed out almost immediately and then ran fine. Shut it down and it started normally about 20 minutes later. Ran it for about an hour and shut it down. I'm going to give it several hours and see if it starts. If it does then I'm going to give it the rest of the day and over night. If it starts normally then I'll be pretty sure it was the injector fuel return banjo bolts or the fuel line connector on the lift pump.
I'll let you all know how this turns out and hope it helps somebody.
I DO know I'm mighty glad I didn't have to pop for a new IP and injectors. If I hang onto this old guy I'll plan for both of those things in a while as with the kind of miles on it I'm sure it will be due.
Thanks for all the help so far. Hope this works!

 

For my 92 - Can anyone point me in the right direction to find a parts diagram/schematic showing the fuel supply and return lines to the fuel tank and lift pump.
I am looking to replace the O rings in the push on connectors to these lines if possible. If anyone already knows the part numbers or where I can get them that would be great as well.
Thanks

 

I am almost 67% certain that the DRAW lines on these trucks are 5/16 and the RETURNs are 1/4.

If you completely replumb the fuel-lines, I would go 3/8 all the way and use JIC fittings everywhere I could.


I had trouble with one of those push-on fuel-line fittings on the RETURN line at the tank on one of the several that are around here.

This particular truck currently has no bed at all, so fuel-tank access is easy.


I had to completely cut off the plastic nipple that the fuel-line plugged on, tap for NPT, and add a standard screw-in hose-barb.

If I had access to the fuel gizmo where all the lines plug onto the tank, I would rework the whole mess with JIC and rubber lines.


BC747 has an excellent pictorial description in the "stickies".

 

BK, you are correct.

5/16" draw, 1/4" return.

 

BC847 Did an excellent write-up and it is in the "STICKY'S"

TITLE:

"Big Fuel Line Upgrade"

Here is the link:
https://www.dieseltruckresource.com/...d.php?t=151190

Best,
Bob

 

OK, After snugging up the banjo bolts on the fuel return lines on the injectors and greasing the push on connector at the lift pump my truck has been starting just fine.
I left it all night and well into the morning and it still started on the first half spin.
Moral of the story is check those banjo bolts now and then. Because I did not see any leaking from the push on connectors at the lift pump when the tank was pressurized I tend to believe it was those bolts.
Still, as soon as I can I think I will replace the hard plastic lines with rubber ones, perhaps in the stock diameters as I am only running about 250 horses and don't plan on cranking it up any more than that. Too many things on the old horse that won't respond well to more power.
Thanks for all the help - reading the Stickys has been really helpfull and I actually found the fix for a problem that's been driving me nuts for years!
Ron

 

Ron, I have a similar issue with my 93 except that I finally got sit started and then after 10 minutes it quit..the return lines banjo was the issue in yours?..just the ones right below the injectors or is there others somewhere else..I did replace the feed line and Lift pump but not the return.

It's my one and only driver too so any help is great!

 

Loose FSS wire?
Plugged fuel filter?
Gelled fuel?..How cold is it when you where running your truck?

 

FSS gutted, new filter a couple of weeks ago and it's a toasty 85 here in AZ, checked the return line and there is a plastic fitting way in the back of the engine...I can see it with a mirror but a bear to undo or change did clean and grease the return line at the tank...tightened the 10ml nuts on return line and they were pretty tight, some a less than quarter turn still got prime at the LP after replacing feed line to it from tank...not sure why it ran for only 10 minutes...any clues?

 

Ron probably won't help you, as we haven't seen him here in about 5 years or so. This thread is older than that.

Best to start a new thread describing all you've done, your vehicle description, mods, etc

 

I wondered as it was a while back but he did seem to fix it and it's a 92 he had...wondering some say the return line is not affecting the running of truck some say it will keep it from running..which is it?

 

Thanks NJTman did start the new one here https://www.dieseltruckresource.com/...8/#post3339178