No start Lly

[Edv2003]

Hello, I'm new to forums so please bare with me.
Bought a 2005 2500hd with a Lly duramax in "not running" condition. Sitting for several years. 440,000km on the clock.
Cranks but won't fire. It's think about trying to fire when first cranked up then spins fast.
Tried some ether to see if it had any will to live. No luck.
Cracked high pressure line off of cp3 pump and had very poor fuel pressure.
Replace cp3, put everything back together, still giving me the same run around.
When hooking up my obd scanner I'm able to get sensors values but no DTC codes, same with a tech2 scanner. Seems fishy to me.
The other question is; when cranking the intake sucks air in and blows air back out at me which also seems like an issue.
Any ideas on any of my problems? Any help is appreciated. Thank you.

 

[2004LB7]

can you see the fuel pressure pids?

 

[Edv2003]

can you see the fuel pressure pids?

Not with my current scanner. Can see excellent pressure when cracking lines at injectors. Unsure if injectors are trying to open or not at this time.

 

[2004LB7]

seeing fuel at the high pressure lines 8s good but if you don't build the needed pressure then it won't fire. you need to find out if it is building the 1500 psi needed to fire the injectors

 

[KyleC4]

Air comes back out at you from intake? Only time I’ve ever ran in to that was plugged exhaust. Truck usually started first then stall and won’t fire again. MAF readings would be all over the place

 

[JoshH]

If it won't run on ether, you have a mechanical problem. I would start looking at why it is blowing air out of the intake. I've seen them to that before if they spin the cam gear.

 

[Edv2003]

If it won't run on ether, you have a mechanical problem. I would start looking at why it is blowing air out of the intake. I've seen them to that before if they spin the cam gear.

More or less what I suspected was really wasn't wanting to hear. Thank you very much. Tear down starts this weekend.

 

[Edv2003]

Air comes back out at you from intake? Only time I’ve ever ran in to that was plugged exhaust. Truck usually started first then stall and won’t fire again. MAF readings would be all over the place

Exhaust is off.. I'll start tear down and inspect. Thank you!