detroit 14l skip, never seen this before, need advice!

I will try to make this as short as possible. I have never seen this problem before. 2006 Columbia with a Detroit 14l. I was coming home empty the other day traveling thru the rain. I pulled up to fuel and the truck would not shut off with the key! I searched the forums here and found someone who had the same problem... Water leaking into the B pillar behind the drivers seat and right onto the pdm! (I think that's the pdm with fuses, please correct me if I'm wrong) I dried it off best I could and left the panel door open so that the water could no longer touch it and it would be exposed to the heater in the cabin which would help it dry.. Later in the day the switch began to work again and everything seemed fine. As I arrived home from the long trip I began to notice that the truck had a skip. Under wide open throttle it just coughs and sputters and the boost gauge is going to zero and back up to full boost very quickly. Shift gears, and run WOT and it may run clean and normal thru the next gear or it may stumble again. It seems 10th (10 Spd) is the worst. It's very unpredictable, but it seems to stumble less noticeably under 50% throttle or less. Engine has all deletes for egr, vpod, it has a standard (non vnt) turbo etc.. No codes but when driving the truck down the road with a computer monitoring the engine, the engine load at WOT will be 100%, and when the stumble starts, the engine load will go to 0% and right back to 100% when it quits. This all happens very quickly! Freightliner man says he has never seen this before. The TPS also reads 100% when at WOT and never falters. The only thing I know to do at this point is to start throwing parts at it. I am going to start with the PDM since this problem seemed to start after it got wet. Then cam and crank sensors and a injector harness will be in line afterwards if the pdm doesn't fix it. Next I plan to start with a fuel pump although it doesn't act like its fuel related to me. The truck already has a brand new fuel regulator on the back of the head, engine harness to ECM and ECM to firewall harness so that is not the problem. I have also tried another ECM, and that is not the culprit neither. Any ideas will be greatly appreciated!