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2004 Chevy 2500hd, 2006 Chevy 2500hd
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Discussion Starter #1
I picked up an 04 lb7 from a buddy, he says it ran fine, he parked it and when he tried to start it a week later it won't start. I have checked for fuel leaks, made sure it is primed, tried pumping the primer while cranking and still no start. Security light isn't flashing, no codes, all fuses are good. I have 6000 psi rail pressure while cranking. I believe it isn't getting fuel, there's no smoke or fuel smell from the exhaust while cranking. Any ideas? I have access to a good scan tool so anything else I should check just let me know.
 

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Welcome to DieselPlace
When you attempt to prime does the button stay hard?
 

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2004 Chevy 2500hd, 2006 Chevy 2500hd
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Discussion Starter #3
Welcome to DieselPlace
When you attempt to prime does the button stay hard?
It does until I try to start it, then I can push it 3 or 4 times until it's hard again. With 6000 psi of rail pressure, doesn't that mean it's getting fuel to the injectors?
 

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It does until I try to start it, then I can push it 3 or 4 times until it's hard again. With 6000 psi of rail pressure, doesn't that mean it's getting fuel to the injectors?
6k pressure should be good enough for idle, so yes, fuel is getting there.
Have you opened the bleeder screw when priming to purge any possible air?
You have pulled the IGN 1 relay to verify it is intact and good?
 

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02 2500HD LB7
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How good are the batteries? If they are weak, the voltage might be dropping too low during cranking.
 

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2004 Chevy 2500hd, 2006 Chevy 2500hd
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Discussion Starter #6
6k pressure should be good enough for idle, so yes, fuel is getting there.
Have you opened the bleeder screw when priming to purge any possible air?
You have pulled the IGN 1 relay to verify it is intact and good?
Yes, no air bubbles that I could see came out. It doesn't have an ign relay, but I checked all the ign fuses and swapped the edl relay with a known good relay.

The batteries are both new and fully charged
 

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02 2500HD LB7
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Do all the IGN fuses get power when the key is on? The big IGN A only sees power during crank so ignore that one.
Could possibly be the ign switch on he column not sending power to all the right places.
 

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2004 Chevy 2500hd, 2006 Chevy 2500hd
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Discussion Starter #8
Do all the IGN fuses get power when the key is on? The big IGN A only sees power during crank so ignore that one.
Could possibly be the ign switch on he column not sending power to all the right places.
Yes, checked both sides of each fuse to ensure one wasn't blown. Power to all the ignition fuses except ign a
 

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2004 Chevy 2500hd, 2006 Chevy 2500hd
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Discussion Starter #10
Well I found something interesting. Pulled the intake tube off to spray some wd40 in to see if it would fire, and it alternates sucking and blowing out of the intake while cranking. So I'm thinking sheared can pin or something else broken in the valve train. It's just odd it didn't make any noises when it was last turned off.
 
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