Help 7.3 missing, no codes, did buzz and contribution tests

[SICKS-O]

no problem, did the best i could for 3am lol. since you have OKed the wiring before spending any money or getting your hands to dirty i would test the resistance of the injector coils with a digital volt meter, i dont think you will be able to do it easily without the tool they sell that plugs into the valve cover gasket, it has color coded pigtails for dvm leads. you may be able to make your own test harness if you have any spare harnesses laying around.
i think the easiest thing to do would be to uncouple the junction block that is on top of the drivers side valve cover and test the injector coil resistance from the pins on that block, of course you will need to know which pins are for the injector circuits. when i get another break at work i will grab our 7.3 service manual and post the acceptable resistance range for the injector coils. following this procedure will save you time and trouble. if the resistance of any of the injectors doesnt check out then you will know you will need to replace them, if the resistance is good there is still a chance that an internal part of the fuel injector(s) has failed and i will try to help you diagnose further.

-Joe

[Tempsho]

Lots of good information in this thread for troublshooting a 7.3L that's missing! Good luck with your problem and let us know what fixes it.

[Probuilder]

Does anyone have a link to a wiring diagram for the junction block above the drivers side valve cover? I am looking for one that will tell me which wires run to the injectors, to test them.

Sicks-0, First thank you for all your help.
Why am I getting a P0475 and P0476 code in the computer? What is this pressure valve? Now I am not getting the boost that I used to either, and the truck is consistently getting worse, as far as running and power.
KOER:
P0476 Exhaust Pressure Control Valve Range/ Performance
KOEO:
P0475 Exhaust Pressure Control Valve
Just a thought, but if my EBPV sticks when I am warming the truck up, it will smoke and have no power. Could this be a problem, and defueling the truck? Or would that not have an effect on the buzz test? (Probably not but just a 4 am thought that ran through my head when I quit working on it last night)

Again thank you all for your help.

[907DAVE]

I can shoot you some diagrams if you like, just need your e-mail address.

[Probuilder]

Dave,
Probuilder72@gmail.com
Thank you

[907DAVE]

You got mail.

[Probuilder]

I cleared all codes, reran the tests, KOER and KOEO. This was all done after checking the resistance on all injectors. They all come out the same and with in specs.

These are the new codes that I get with the AE Scanner on my laptop.
P0475
P1280 ICP too low.

Now on the idle I am running a Injection pressure of 481.96 psi and at 2200 rpm it is at 1153.2 psi. Do these numbers sound right?

The truck is the same as before, so no change.

[907DAVE]

Just for giggles try running it with the ICP disconnected......or have you done this already?

[907DAVE]

And just so we are all on the same page here - the truck is missing at idle and under load, correct?

Would you guess it is a steady miss, or more of a random misfire?

There are no more CCT faults?

No actual CEL when running?

[Probuilder]

And just so we are all on the same page here - the truck is missing at idle and under load, correct? correct

Would you guess it is a steady miss, or more of a random misfire? Steady

There are no more CCT faults? none

No actual CEL when running? no light

I will try the CCT with the ICP unplugged when I get back home.

But why is the P0475 code in there?