So I've been finishing up an 06 that we pulled out the engine and did studs, etc. Also had a heck of a power steering leak so we cleaned up the engine bay while the motor was out.

Got the motor in and everything back together on Friday. Pulled the FICM relay and cranked till the ICP came up. It would only build 300-350 psi and then level off. It was late so I left it till today figuring I'd pressure check it and fix the leak and be good to go.

Went to unplug the IPR to plug in my controller and found the IPR plug wasn't seated well. Plugged it back in, same result. Plugged in the controller and ground the IPR and the truck would build 4000 psi. So the IPR is good. I noticed the duty cycle wasn't changing from 14.84%. Almost like the IPR was unlugged.

Checked for voltage at the red wire on the IPR. Voltage good. Other wire goes to ground good. So the pigtail is good. Then I was stumped. Did a fair amount of research. Tons of info for DC at 85%, none for it being stuck at 14.84%. Until I came across a 7.3 related thread. Seems with the 7.3, when the cam sensor is unplugged, the DC won't change from 14.84.

Of course the 6.0 has CKP and CMP, so which one to check? Back to AE. Cranking I had no RPM signal and no CKP/CMP Sync. According to what I found here, no RPM and no sync = bad CKP. Unbolted the AC compressor and sure enough, somewhere along the in and out with the engine, the CKP got crunched. Replaced it and all is well. Well except for a small oil leak because I nicked the oring at the base of the oil filter housing...

Couldn't have figured it out without AE and FTE.

tl;dr - it was the CKP

 

Great post! Much appreciated!

 

Thanks for posting a problem and a solution.

 

Your awesome Bud great diagnostic work thanks for posting

 

You rock Glad you got it going

 

Very good trouble shooting and something to remember.