Hello from Texas

[white5500]

Hi every one, I am new to the site.

I have pulled all of my hair out messing with our new truck and need some help figuring out why our 08 c5500 always goes in to limp home mode with a load.
It gets a p0087 code and defuels so bad the truck won't even hardly move.
It has been at two different Chevy dealers and multiple shops no one can fix it.

Any help would be greatly appreciated

Thanks Michael

 

[emiller3]

:welcome2:

 

[blk smoke lb7]

Welcome to DD

 

[Trotorx2]

Welcome...

Have you checked the fuel lines coming from the tank to the filter? I believe there have been some problems with pin holes and fuel lines kinked or collapsing.

 

[fun w son]

welcome here!

 

[Kat]

:hello: and :welcome5:

 

[white5500]

Thanks for the welcomes. I will look at the lines, I have tried everything in the world to figure this out.

Dropped tank checked pickup, Added lift pump and new filters, replaced rail pressure relief valve with blank, replaced cp3 regulator, replaced the rail pressure sensor, deleted the particulate filter and retuned with an H&S downloader. I hate this truck.

I went and bought a scantool to try to figure this thing out.

I looked at fuel pressure when this happens and it is very high. It says it is supposed to have 26,000 psi and the pressure stays pretty close to that. I looked at the duty cycle to the regulator and while towing pressure appeared to be good and the duty cycle stayed under 30 percent. At this point i am lost and any help would be greatly appreciated.

Again thanks for the welcoms guys and thanks alot.

 

[Trotorx2]

Where are you located? Maybe one of the vendor shops from here is close by that you can go to and let them help.

Sorry I not much help. I had the same code when running my race tune and I had to have the threshold that trips the code changed with EFILive and I haven't had a problem since.

 

[Texas Chevy]

I hear alot about the straw in the tank that sucks the fuel up having a crack or something. I am no mechanic so I don't know to much but I have had it happen on my boat and blazer just throwing out ideas

 

[lavacarancher]

I am certainly no expert on diesels but I had a customer come in one day with a problem similar to what you describe in a gas Chevy 2500. It would absolutely shut down while attempting to pull a load. I looked at everything including cam timing, spark timing, fuel pressure, air flow, disassembled carb (twice), pulled the engine and disassembled (looking for ?). Nothing was out of place. While underneath the truck with engine running I noticed by accident that every time my buddy tried to race the engine the exhaust pipe would move back. Strange! I disconnected the exhaust pipes from the manifolds and the truck came alive. Turns out the inner exhaust pipe was collapsed while the outer pipe was perfectly round and showed no signs of damage. At that time I didn't know that GM used a two layer pipe for their exhaust and have no idea if they still do that or not. I had never heard of such a thing before then nor even up to now. Once in a life time occurrence and I'm not suggesting such a thing on your truck. Just suggesting you've checked all the obvious things, try something not so obvious. Good luck to you. It can be really frustrating sometimes.