Crank NO Start 2002 2500HD LB7

[dgalvin66]

I have a 2002 GMC 2500HD LB7 with a Crank NO Start problem.
This happened about 4 years ago and turned out to be the filter head. I just replaced the filter head, filter and the 2 fuel lines coming of the housing and it still does not start.
I have a basic code reader that is showing no codes. I know someone that has a Tech II scanner and trying to find time for him to come over with it to see if it tells anything.
I do NOT have the money to just start throwing parts at it in hopes that something will fix it. Please tell me what to check and how to do it to try and determine the problem. What tests to run when I get the Tech II here?
Thank you

 

[2004LB7]

How does the primer bulb feel when pumping it? Does it get hard?

Have you tried replacing one hose going into the CP3 with a clear one to see if you are getting air in the line?

Do you have a lift pump?

 

[dgalvin66]

The truck is all stock, No lift pump.
I loosened the screw on the head and pumped the primer until fuel came out solid and closed it then pumped until hard.
No clear hoses, I replace the 2 hoses with OEM hoses, what a pain in the butt the do them.

 

[2004LB7]

Yes. Those hoses suck to replace.

When you introduce a large amount of air into the system like you did when you replaced the filter head and hoses it can be hard to brake the vapor lock. Typically you have to pump until hard, crank for a few seconds. Rish and repeat. You might have to do this a bunch of times to get all the air out. Sometimes it helps if you have a buddy pump the primer while you crank the engine over.

Lift pumps make this process a breeze

 

[dgalvin66]

I will try to bleed it some more and try it.

 

[2004LB7]

Some have had luck putting a little air pressure into the fuel tank. Like 2 psi. Just enough to help the fuel move up the line

 

[dgalvin66]

I am going to try bleeding and priming it again tomorrow. I will check to see if I have enough air line to run it to where the truck is parked and give that a try. what will that test tell me if it works or doesn't?

 

[2004LB7]

It's not a test. Just helps priming the system

 

[dgalvin66]

I purchased a bluetooth OBDII and downloaded some scanning apps onto my tablet. I'm not sure of what to be looking for but I did get a little info.
Desired Fuel Pressure 6090 = Actual Fuel Pressure 5960
Fuel Pressure not running is 145 psi
I pulled a few codes that my reader did not get.
U1000
B2961
B2973
B3138
Does any of this help with figuring this issue out?
what tests can I do to test the FICM or ECM and Injectors?

 

[2004LB7]

U1000 Class 2 Data Link Malfunction
B2961 Key left in Ignition Circuit BCM DTC
B2973 LF Door Key Switch Circuit Low
B3138 All Door Lock Circuit High

Only one of concern right now is U1000

Fuel pressure looks good. So maybe the reason for the U1000 is keeping it from starting

For testing the FICM & injectors, you'll need a scope and LCR meter

 

[dgalvin66]

How does the primer bulb feel when pumping it? Does it get hard?

Have you tried replacing one hose going into the CP3 with a clear one to see if you are getting air in the line?

Do you have a lift pump?

What size fuel line is it? I will get some and try it. No I do not have a lift pump.

 

[2004LB7]

I believe 3/8". I just use some of the vinyl hose from the hardware store that looks to be the right size.

 

[dgalvin66]

I'll pick some up to try. How long would you say it should be?
Any suggestions on getting the current hoses off without too much fight?

 

[2004LB7]

I don't remember the length. I think the last time I had to do it, I purchased 3 feet or something. Only cost a few dollars so not a big deal to get more. From the filter housing to the FICM banjo is only like 14" or so. But if you want to bypass that and run right into the CP3 then 3' should be enough

If you struggle to remove the old hoses. Might be best to replace them. Just a slight twist and pull normally does it for me. If it's stuck on. Then I may cut it off. Depends on how much slack it has and if I'm willing to replace that line right after

 

[dgalvin66]

I don't remember the length. I think the last time I had to do it, I purchased 3 feet or something. Only cost a few dollars so not a big deal to get more. From the filter housing to the FICM banjo is only like 14" or so. But if you want to bypass that and run right into the CP3 then 3' should be enough

If you struggle to remove the old hoses. Might be best to replace them. Just a slight twist and pull normally does it for me. If it's stuck on. Then I may cut it off. Depends on how much slack it has and if I'm willing to replace that line right after

Trying to get them off without cutting them since they are both brand new OEM hoses and they are on very tight.

 

[dgalvin66]

U1000 Class 2 Data Link Malfunction
B2961 Key left in Ignition Circuit BCM DTC
B2973 LF Door Key Switch Circuit Low
B3138 All Door Lock Circuit High

Only one of concern right now is U1000

Fuel pressure looks good. So maybe the reason for the U1000 is keeping it from starting

For testing the FICM & injectors, you'll need a scope and LCR meter

I finally found my old tablet to install Torque Pro App on. I am trying to set it up to get the injector balance rates but it reads "0" when I crank. Is that correct or should it read something when cranking?
I had a friend come over a few weeks ago with a Tech 2 and he cleared all the codes. He does not know anything about diesel and did not know what tests could be run. I am learning this stuff slowly and hope with everyone's help to get this running again.

 

[2004LB7]

Balance rates are only during idle

 

[dgalvin66]

Balance rates are only during idle

OH, OK. Someone on another post had said to check them with this problem.
What tests should I be trying to run to help figure this out?
Still have not gotten the new hoses off.

 

[2004LB7]

You need fuel pressure, crank and cam signals in sync and no security VATs issue for the system to start. Also, a working FICM

Once started, then get balance rates

PS: torque app isn't really a good option for diagnostics on these vehicles

 

[JoshH]

OH, OK. Someone on another post had said to check them with this problem.
What tests should I be trying to run to help figure this out?
Still have not gotten the new hoses off.

They were probably saying to check injector return rate. Worn injectors that are returning too much fuel can cause them to not be able to build enough rail pressure to start, but since you are building desired rail pressure while cranking, that doesn't sound like it is your problem.