Help Needed with 7.3 IDI - Starts up then Dies, no start now

[scjarena]

I have a 90 F350, 7.3 IDI, for the past year starts right up no problem. Over the past month, I noticed it getting a little harder to start, had to crank on it a few more times. Then last couple weeks, it would start ok, then die out right away, after some cranking it would finally start. Yesterday, started up, died, now doesn't want to start. Any help diagnosing the problem would be appreciated.

Batteries are still good, I think glow plug system is fine. I don't think it is puffing black smoke while starting so I'm thinking fuel problem.

 

[quickster]

Might be time to replace your return lines. Sounds like air intrusion.

 

[Randy Bush]

2x /\

 

[scjarena]

I'll look over the return lines, but I don't remember seeing any fuel leaks, at least around the intake area and around the injectors.

 

[quickster]

You don't always get leaking fuel. The lines pull in air. If they are braided, look for darkness or feel them for brittleness. I don't like braided myself

 

[quickster]

I read a while back that the shorter the run time before it dies, the closer the leak. So if it runs a few seconds, the leak should be up top.

 

[miles1400]

air intrustion. alot of people recomend checking the return lines, also check the hard lines and the filter head aswell

 

[Randy Bush]

I was having trouble with a couple of mine . Installed a check valve before the mechanical fuel pump solved the problem.

 

[scjarena]

I found a loose return line near the filter. Fixed it, bled some of the injector lines and it started right up. I'll let it sit over night and try it in the morning. Hopefully that was the problem. Of all the different old school diesels I've owned the IDI seems to be the most ****** about air intrusion.

 

[papadiesel]

Mine were not wet and looked fine, they can suck air and not leak. I replaced with quality set, start went from 10plus seconds to 2-4 seconds.