1992 F 350 Navistar 7.3 IDI

[johnQ1]

Seems I lost this post so I am trying again.

I am working on a starting problem with a non turbo Navistar 7.3.
I have checked glow plugs found two bad and replaced them but still have the same starting problem.
The truck will run great after starting but takes several 30 second cranks to get it going after it has been setting for a few minutes. This problem is not only associated with a cold start.
It is like the fuel bleeds off from the injector pump a few minutes.
I can't find any leaks other than the one I created yesterday while changing a glow plug it seems I may have disturbed a O ring on the return line and now have a leak there.

Any help or additional ideas would be appreciated.

 

[icanfixall]

Welcome to the forum. What your problem sounds like is the fuel appears to be draining back out of the filter and that sucks the fuel out of the injection pump. I suggest that you try tightening up the brass nuts on the injection pump feed line from the filter and the single nut on the filter supply line. In those brass nuts on the lines are seals called olives. The dry up and harden and that causes air leaks. You will get an air leak long before a fuel leak because of the smaller molecule size of the air compared to the fuel. If you want to replace those seals they can be purchased at any good injection pump repair shop. The injection pump feed line olives are 5/16 and the filter supply line size is 3/8. They can be difficult to remove from the brass nuts too. Soaking over night in brake fluid softens themand a dental pick will dig them out.s

 

[johnQ1]

Thanks I will check that out this morning. I was thinking it may be something like that after a leak developed on the #2 injector after I changed the glow plug for that cyl.

 

[johnQ1]

Replaced the injector return O Rings and hoses and the engine starts and runs like a top. Not a bad job too me about 3 hrs to complete and the truck seems to run a little better than before.

 

[icanfixall]

Glad you have it fixed and running nice now.