A little background on the truck.
I just got done doing a headgasket job on a 2003 6.0. The truck had a known Hg problem for at least a year with excessive pressure in the coolant bottle. It all of a sudden started running very poor and wouldn't accelerate. After the headgasket replace with headstuds it started very nice but you could tell had a miss. It ends up being cylinder four isn't firing. It will start right up when cold and run for maybe 1 minute until it completly shut down the left side running on only four cylinders. I was instructed to check the ficm so I try the test for the seven pin and I get under a volt. I've read a lot about the same situation on the ficm but those truck did not start at all. All fuses and relays check good

 

which pin did u test on???

 

The very top pin in the row of four

 

So the FICM is dead then... replace it. PM me if you want, I can walk you through the test and I can also fix these.

 

I was talking with a buddy of mine, a diesel tech at the ford dealership, and he thinks its not
the ficm. I pulled the cylinder four injector plug an now the truck will idle and not lose the other three cylinders on the left bank after 40 seconds

 

One Volt on the FICM as long as you are checking the right lug=bad FICM or perhaps wiring harness. Batteries in good condition? Load test them. Good luck bro. One thing I'm learning with the 6.0L is never jump to conclusions on trouble shooting. Things are never what they seem to be!

 

I figured it out last night. The injector at cylinder four had a short in the solenoid causing the rest of the cylinders on the left bank to quit. I put a new injector in it and she runs good

 

Never heard of that before...

 

Neither have I but I am glad to have figured it out. the diesel mechanic at one of the local dealerships for 12 years hadn't either

 

She still has a problem.....

It runs decent but now is lacking power. It feels like its towing a massive load. The granny isn't in good shape but it wasn't before and never acted like this so im ruling that out. The turbo was cleaned less than a week ago as was the exhaust pressure sensor and tube. Egr is deleted with a sinister kit, head gasket was just replaced with arp studs and new stand pipes. Intake is a cold air k&n kit. Has a 4 inch DP.I checked the ic boots and they all are in good shape. When the owner gets home from work I am going to check voltage on the ficm I did a vgt relearn and drove mixed driver for probably 30 miles and ran the **** out of it and still it has no power like it used to. The owner installed a tune from a sct livewire and you couldn't tell