Ford F-150 (2004-2008) :: Power Shuts Off For Two Of Injectors / P0351 And P0356

2004 f150 5.4

When I start the truck it runs fine for roughly ten seconds then it shuts off power to two of my injectors. Or so I thought. With a noid light on, I was getting shutdown on cylinders 1 and 6 as per the codes ten seconds after starting. I assumed this was as intended to stop raw fuel from entering the cats.

So far this is my findings. Noid light-shuts off the two cylinders after ten seconds. But will pulse again later before shutting them down again. Truck idles better, but never seems quite perfect. Could just be how 5.4's are though.

Swapping injectors did not change codes.

Coil packs are working on those cylinders. Spark test checked out and plugs are firing. They were replaced at some point with oem motorcraft plugs.

ohm test showed wiring to those cylinders was fine. Wiggle test showed the same.

The truck revs and sounds great before it shuts off power to the cylinders. I cannot assume a mechanical failure at this point. I have not ran a compression test on it yet as, in their great wisdom, Ford determined they had to be different than the rest of the planet with spark plug sizing. Adapter will be here tomorrow for me to verify that part.

I have checked around quite a bit so maybe this has been somewhere else on the site and I missed it. I have exhausted everything minus a compression test. I can only point a finger at the computer currently. But I am not quite sure how to verify that is the issue. And quite frankly, I have never seen a computer go bad without outside interference.

On a sidnote, the truck starts very hard at times. Like a car that has heavily advanced timing. It could actually just be a starter issue though. I figured I would get to that after I find out what the other issue is.