Hello everyone. I've been coming here for a long time for answers. I just recently joined so I'm new and hope I'm posting this in the right place. Ok so I have a 200,000 mile f350 drw that I just installed new head gaskets, studs, oil cooler, water pump, all new orings and seals that go along with it. New stand pipes, dummy plugs, ipr valve, blue spring kit. 2 injectors. The truck was starting fine when I parked it for I knew I was losing a little coolant through the right bank head gasket. So I did the said work to it.
so after priming it fired with a little rough idle but shortly smoothed out. After idling for a period I touch the throttle to bring the RPMs up and it instantly dies. Like shutting the key off. No spit, it maybe a split second of rpm elevation then dies. And after 50 attempts there's zero change in it's actions. Does the identical thing and shuts off. It will idle for as long as you want just don't touch the pedal.
So here are my test results using a matco tool pro reader. Well first off I tapped the cap at the fuel bowl and have a constant 65psi . And it stays there. 2 new filters as well (motocraft) low oil pressure is instant showing on the dash. Icp pressure runs about 680 on idle with the ipr at 26% . Camshaft and crankshaft sync is good. Ficm sync to injectors is good.
When I earlier said you can get ever so slight rpm rise before it dies. If you watch the fuel pressure you can see it does rise from 680 to around 1000 before it dies. Ficm voltage rides right at 48 and only drops to 47.5 occasionally. The truck immediately fires back up with little cracking time. No other red flags I see in the scan tool. (I know it's not the best scan tool but I think it's ok) I ran koer with no red flags. Koeo injector scan with no red flags.
I'm at a loss. The only thing I can possibly think of and I'm hoping you guys could confirm. Is my engine harness is gnarly. I did pull it off and back on with the work. It's oily. Nasty and looks like it was run over by a school bus. (I guess from years of leaks, worked on etc) am I looking at a short somewhere? Thank you for taking the time to read and possibly help.

 

I think I may have pulled the bonehead move of the year without realizing what I was doing. After speaking with a gentleman who owned one and is fairly familiar with them brought it to my attention.
so after pulling the cab I wanted to completely remove the harness out of the way just to not have it hanging in the way. But the was one wire that looked like it was a pain in the Keister to get to the connection so I said (screw that I'll lop it off quick and connect it later) as you already know and probably guessed. It was the crank sensor harness. I know I know. I'm an idiot. I get it. The gentleman told me it may be a shielded ground running parallel in the harness or something of that nature. When I repaired it I did see a bare 3rd wire along with aluminum foil wrapping. I only crimp connected all the wires. He told me to start the truck and watch the sync connection on the scan tool as I tried to throttle the engine. In the previous post I had said it would shut off if you simply pressed down on the pedal. But if you give it a quick jab it would cut out but if you did it quick enough it would remain idling. So I watched the sync and when I did the jab the cam/crank sync flashed from yes to no when it cut out. Then back to yes on idle.
So did my bonehead move just cost me a complete 700.00 wire harness that may be hard to find? If so. I'm a little Leary about buying aftermarket harnesses as well. And of course there's lots of used ones available but most are 300.00 and what am I getting?
Unless there's any possible way to do a correct repair on the harness I cut off. I'm definitely willing to take the time I should have in the first place to repair it. I guess I should ask first if this is my culprit? I'm assuming so? Any help would be greatly appreciated. And yes I should of known better and lessen learned if that's the case. I just was unaware I was possibly cutting the worst wire in the harness to cut.