2004 LLY Crank no start need help!

802duramaxlly

New member
Mar 26, 2022
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Hi I have been fighting a crank no start for 4 months now with no luck any help would be greatly appreciated. The motor was swapped into a different body same year truck, I did head gaskets and head studs while the motor was out. I used everything from the other truck, all wiring harnesses, computers, steering column, BCM, TCM, FICM, used the Duramax frame, just different cab. I have a p0089 fuel pressure regulator code, high fuel rail pressure about 18,000 psi and desired is around 6,000. I just put in a new fuel pressure regulator , same issue. The truck doesn't even smoke or want to turn over, just cranks crank cranks. I just installed a lift pump and deleted the fuel filter housing, I tried my FICM in another durmax and that truck ran great. What am I missing? Checked all grounds, checked fuses, did key relearn multiple times. does not show oil pressure while cranking either Truck has great compression as well.

Thank you

Casey
 

802duramaxlly

New member
Mar 26, 2022
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I had a couple anti theft codes but I got those to go away, any reason it still could be and isn’t throwing a code or showing security light? Is there anyway to bypass anti theft all together? How could I test the cam and crank sensor

Thanks
 

4dailyrunner

New member
Mar 26, 2022
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crank and or cam sensor

While researching this model, I saw quite few YouTube videos about this. The piece that holds the sensor (1) bends (2) is defective or (3) vibrates loose.

The sensor disengages and becomes an open circuit.


Sent from my iPhone using Tapatalk
 

Jakezed22

Active member
Dec 2, 2016
255
125
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X2 on crank or cam sensor, have You triple checked they aren't plugged in wrong? Like cam in crank and vice versa
 

79LT1Monte

New member
Apr 18, 2022
4
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1
Are you seeing RPM signal on your scan tool? If you see RPM and it's not smoking while cranking I would lean towards cam sensor