7.3 no start

[djusc122]

hey guys. ive got a crazy 7.3 that wont start. ive got the crazy idm relay clicking. ive done a lot of overlays and still nothing. had the pcm rebuilt early but nothing. any input.

[diesel71]

what test results do you have?
icp pressure cranking?
injector buzz test ?
icp regulator % ?
fuel psi ?
do you have cam signal ?
codes ?

[djusc122]

icp 1500 to 2000 cranking
ipr 36 max
good rpm
good buzz test
fuel around 46 47
only code is 603 which I have seen in running trucks

[djusc122]

I can hear the idm relay on and off
testing the relay while cranking the signal from the pcm that grounds the relay is on and off
ive cleaned the pcm grounds overlayed the grounds checked the voltage at pcm and overlayed them
also overlayed the ground wire from pcm to relay

[diesel71]

sounds like a bad idm, do you have a test one?

[djusc122]

the relay gets its signal from the pcm not the idm. why would you think idm

[Witsend]

Basic thing?

Just because you have Good ICP (which is basically the high pressure engine oil system) doesn't mean you actually got clean diesel fuel at injectors. Check the fuel quality . Un obstructed Air ? Blocked solid air filter? Corked exhaust Whats the EBP (exhaust back pressure ) KOEO versus cranking? Seems I recall a few even had the connectors inside the valve covers detached at the gasket. Other than that I would probably lose my *** on one

[diesel71]

the relay gets its signal from the pcm not the idm. why would you think idm

a bad idm will cause that relay to cycle, seen it befor and you said you have the 603 code.

[djusc122]

Believe it or not. The pcm is bad. I've got a used one here at the shop and it starts the truck. Been chasing my tail. Got another one ordered.

[Witsend]

Cool, Were you able to do the necessary PATS key programming with you Solus Ultra, or was the truck old enough that it did not have PATS?

[djusc122]

no pats on this one. lucky