Im stumped!

[AllJackedUp]

Ok gents, so i got the rebuilt IP (u haul) in my buds truck and new injector return line kit. I just have it static timed for now. the truck started after i got the air out of the system and ran pretty good. I took it out to put some fuel in it and when i took the fuel cap off the front tank, which is the one it was pulling from, it looked like exhaust smoke coming from the fuel tank. the truck was running while i was filling and i didn't think any more about it. so my buddy picks it up a few hours later and all was good. Then he starts it this morning and notes that it takes awhile to start up. He gets about 15 miles down the road and smells diesel really strong. He pulls over and sees fuel squirting out of the #2 return cap. it had a pin hole in the side. so he calls me and i bring one of the old ones and put it on and send him on his way. a few minutes later he calls back because it happend again. #2 cap has another hole in it. When i pull it off it looks like it burned through it. Also the area on the injector between the o rings is very carboned up. Its like the combustion gases are coming back up through the injector and through the return line to the tank.
sorry for the long post, but has any one ever had this happen? I am kinda thinking when the old IP shelled out that some debris messed up the injector?
BTW the truck is a 93 with an 88 van 7.3 idi
Thanks for any help.
Ryan J.

 

[towcat]

but has any one ever had this happen? I am kinda thinking when the old IP shelled out that some debris messed up the injector?

you have compression gasses blowing back through the injector.
very very bad. stop driving and change out the injector. hopefully the injection pump didn't get ruined.

 

[AllJackedUp]

i sure hope the new pump isn't hurt. it wasn't too hard but i don't wanna do it again. It looks like u haul does not have anymore injectors. should i change them all or just the one.

 

[towcat]

i sure hope the new pump isn't hurt. it wasn't too hard but i don't wanna do it again. It looks like u haul does not have anymore injectors. should i change them all or just the one.

critically, just that one.
ideally, all

 

[icanfixall]

The way you have worded this posting it looks like you replaced the injection pump and the return line kit.... But not the injectors soo... I'm thinking you got some dirt in the injector thats hanging open or that injector just finally let go because of age... The injectors and pump usually last around 100,000 to 150,000 miles. They degrade so slowly we usually don't see the power loss... But injtall a new set and WOW... It comes back to life.... So as towcat posted you can replace the single injector thats bad but its best to replace all of them. When you install some new but leave some old in the engine they pop open at differant pressures. That in itself changes the individual cylinder timing... A low pop pressure will be an early or advanced cylinder timing and a high pop pressure will be a retarded or late cylinder timing.... You will feel this... Try to replace all of the injectors but if you can't afford it just run it till you can knowing full well its not right till its done right....

 

[AllJackedUp]

Thanks again fix all. Yes you were right, I replaced the IP and return kit but not the injectors. I found new delphi's on thedieselstore.com for about 25 bucks a piece. seems like a pretty cheap price.

 

[BigRigTech]

This happenened to me on the 6.9 when I put a reman pump on it....Two of the old injectors turned blue and had the combustion flame going up inside them so I had to put in 8 new injectors.....Problem fixed. I didn't let it run long enough to hurt anything when I saw what was happening.