Detroit 14 Liter Fuel Injector issue

So I had a truck brought to me that the guy said needed an injector. I started the truck and it idled fine. Hooked up my computer and everything checked out. Called the guy and he said it only does it when it sits overnight. So I figured he had an injector leaking down or a fuel problem. Came in this morning to start it to see what was going on. Fired it up and it was smoking and sounded like it was running on 3 cylinders. I ran around to check the manifold and the back three were warming up like they should but the front three were on fire. I did a cutout test and #2 #3 is what I came up with. Pulled #3 first and guess what. Cup was leaking. Put in new cups and since he had three used injectors I put three in 1,2,3. Harness looked ok. Fired it up and it ran like crap again. Ran around to feel the manifold. This time 4,5,6 were scaling hot and #1 was weak. Looked at harnesses outside and did not see any issues. Pulled the doors and came home (past closing time). I put 4,5,6 back where they came from. Anyone ever see anything like that? I plan on putting the old #1 back in in the morning. When I adjusted the overhead all of the exhaust were loose and the injectors were too tight. He had the motor overhauled a year and 3 months ago. He said he already broke two rocker arms and replaced injectors.

 

Was just thinking about the issue. I wonder if the plungers for the injectors are messed up from going too far down. I backed them off 3/4 of a turn. I usually count the turns as I take them down and a few were 1/4 to 1/2 to bottom out.

 

He says it smooths out. I did not run it that long because I did not want the engine to get too hot. Was supposed to be a simple injector swap. I figured with 2 and 3 being so hot that they were just dumping fuel in cylinder. 4,5,6 were ok but now they are hot. I am talking 1,2,3 after starting were 120 degrees and 4,5,6 were 250-300. It was the opposite this morning.

 

He might be in trouble then. I am retired and only do a job every so often. He has been trying to find someone to do this job for over a couple months. I finally told him I would do it but that I could only work on it today or Saturday due to plans I had. I changed up some things and will look at it more tomorrow. I did enjoy opening that radiator cap this morning and having it spew fuel and coolant mix in my face. I missed that so much. (sarcasm)
i would not think that the manifold would get that hot that quick and with that huge a difference in the front three and back three.

 

When I pulled the #3 injector and saw all the rust on the injector I opened the radiator cap and it blew out. It wasn't hot but was under pressure and I popped it off not expecting that. No I drained the coolant and removed all the cups. The #3 was the only one that was bad. The oring had a bad spot on it. I will flush out the coolant system once I figure out the injector issues. I just put water in it for now.