ok, now what? 7.3 no start

[davehatesthisfreakinford!]

I have here a 1997 7.3 that was towed in and wont start. So far we have found:
Burned wire going to glow plug harness, repaired that by replacing valve cover gaskets and harnesses.
had no oil pressure from high pressure pump, replace pump.
removed all injectors, visual inspection (saw nothing)
tested for fuel pressure, has 45 psi cranking.

this thing WONT start. previous person repalced idm,,it was obviously bad, the scanner wouldnt even do a buzz test on ANY of the injectors. re replaced the idm again and get a buzz test just fine and it passes with no problems.
crank sensor is fine, it shows cranking speed while cranking.

engine WILL run on an external source, i know you are gonna cringe, but it DOES run on either with the glow plugs disabled. it will not stay running, dies immediately when nothing is sprayed into intake.

we are at a complee loss where else to look for a problem. any help would be appreciated!

[460+]

Try a used ecm, mabe its fried.

[boltman]

Dave FORD told me when My feul Pump Died... that it should have 90 psi.... Might want to check that....other then that I'd have to have MY mechanic have it for a few days, He's an absolute genius...I will not let anyone else work on my 99 7.3 and he's a GM man ... go figure...

Question, Where are you from? I'm near the Detroit Metro Area...

[forddieseldoctor]

do you have icp pressure after you replaced the pump? If not then you need to make sure you have oil in the high pressure oil reservoir. Then if you checked the injector o-rings I would be going after the ipr. Either blown out o-ring or bad valve. The fuel pressure that you have cranking is more than adequate for this truck.

[davehatesthisfreakinford!]

yes, high pressure when starting to crank is 500-600 oil pressure, i can manually make it (with a scanner)go much higher, (1200). scanner is reading pressure, and it was confirmed with manual guages that it is indeed there. all injector orings are good, they were just replaced also. ipr was repalced with the pump by the way.

this truck has 250k miles on it. it ran fine according to owner when he drove it last, sat for a few months and wouldnt start. thats how i ended up with it.

a previous mechanic said the idm was bad, they repalced it, and never fixed the problemn that caused it to go bad and shorted out the new one too. that was a shorted harness in the valve cover gasket.

i know the idm can control the injectors, it passed the buzz test fine.

I am not auite sure that i am getting them to come on wheile cranking. if i crank long enough trying to get it to start, like 20 seconds or more, i can hear the injectors "popping". but it still wont start.

[kanuck15]

Ok stupid question, how are all the fuses under the hood?

secondly when you turn the key on to turn it over, is there a WTS light?

[davehatesthisfreakinford!]

Yes, the fuses uder the hood are all fine.
the wait to start light does come on.

[kanuck15]

ok id just back trace the harness off the injectors. sounds like a short

[davehatesthisfreakinford!]

harnes checked fine from injectors to idm. it also passes buzz test just fine. we are leaning towards a bad ecm now, but like i said before its an expensive gamble to take.

[kanuck15]

PCM, yeah where abouts do you live? someone close might be able to help ya