I am looking for any info on the following problem. I have a 2005 C5500 with the 6600 Duramax. This is a medium duty truck. I keep getting the code for low fuel rail pressure. This usually indicates a clogged filter, but the fuel vacuum test indicates that the filter is not plugged. Either way, the code will pop again even after changing the filter.
The dealership tested it and found that the vacuum jumped from 3 inches to 18 inches when the engine reached about 3000 RPMs. They replaced the filter housing, the lines to the pump and the fuel regulator. This fixed it for about 1000 miles.
When it does pop a code, it goes into limp mode. If I shut the truck down for about a minute, it can be restarted and run normally as long as I don't let the RPMs climb too high.
Since this is a medium duty truck that weighs a fairly constant 19000 lbs, trying to drive with out going to the high RPMs is near impossible. Any Suggestions?
Thanks

I cant figure out how to foward the file to you but its sounds like the ceramic high pressure valve ball is fractured inside the fuel injection pump. this will lead to internal pump damage resulting in low fuel rail pressure. This is not a recall part but they have had numerous problems with this. give me your email and I will try to forward it to you.