hey we have a 08 duramax that until recently was a bone stock truck... it kept throwing up low fuel rail pressure codes and reducing engine power. we had a diesel tech check injectors and pump to insure they were okay. he told me that these trucks have a tendency to throw low pressure codes and said that he would fix it with tuning when we installed efi live and removed the dpf. the truck ran great for about two weeks while the message to change fuel filter still came on periodically.. my diesel guy told me that the message might come on but we shouldn't need to worry about it. Today we were pulling our backhoe on a 35 ft trailer witch equals roughly 24,000 pounds of load. the truck downshifted to make it up a hill and i was greeted with a very loud bang. the truck then died shortly after. i opened the hood and tried cranking the engine and it sounded like the truck was turning over but the crankshaft pulley was not turning!!!! the only thing i can think of is a broken crank... but the truck only has 126,000 miles on it.. was wondering has anyone heard of something like this happening? and could the efi have caused this by bypassing the engine power reduced message? any help would be great thanks

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i forgot to mention that he did throw on a lift pump and said that was the cause of the reduced engine power message because it needed more fuel... and that was supposed to take care of it.

 

sound like it.

Broken Crankshaft Count? - Duramax Diesels Forum

did you perhaps try changing the fuel filter before all of this?

 

Of course was the first thing we checked.. We could out a brand new filter on, hook up to our back hoe and boom reduced engine power. When the tech put efi live on the message came on every so often, but the truck never lost power, nor the engine light came on anymore. I'm thinking maybe he might have missed diagnosed the fuel rail issue and bypassed the reduced engine power... I was told the message might come on every once in a while but it would be nothing to worry about??? Sounds skeptical to me when two weeks after it left there it blew up

 

i had the same issue with my truck. I had efi tuned by someone in texas and came with the truck. I had the same issues with the fuel filter and reduced engine power.. came down to it being the tuning. I am not saying the tuner you have did any of this I am just wanting to warn you that all of my problems came from a tuner that didn't know his head from a hole in the ground. had my ecm flashed and sent off to a tuner I knew of and trusted his work and haven't had the problem since. I just hope you did your homework on who did the tuning and can tell you that it was the only problem I had with my truck.

 

I'm having the same problem , change fuel filter and low fuel rail press, changed filter repeatedly no change in problem. I did find however that with the tank full i dont have the problem. Doing some research now, thinking maybe an overheating fuel pump IF the pump is in the tank.

 

No in tank pump. The high pressure fuel pump is what pulls the fuel from the tank. It is located in the valley of the engine near the front. It has to pull the fuel all the way from the tank through the FCIM and then through the filter before it arrives at the pump. Any small leaks let air in since it is under a vacuum. Old hoses can be a problem too if thay are collapsing and restricting flow.

 

I'm also experiencing same issues would you know the name of the tuner in Texas?

 

Just to update I've had the efi tune and added a lift pump and that helped a lot. I know I put a bandaid on it but don't know what else to do without spending loads of money at the chance of not finding the actual cause. At least now I don't have to stop and prime my filter and it rarely acts up now.

 

Chances are if you put a lift pump on the truck and it helped bandaid the situation it is a safe bet the CP3 is the culprit. Something to keep in the back of your mind somewhere down the road.