04 Duramax Surging up hill while pulling 5th wheel

manderson72 · 07-01-2009, 10:23 PM

I have a 2004 2500HD with the LLY Duramax. Every once in a while it surges while pulling up hill. I have to keep it under 2000 rpms or pull over and restart the truck to make it stop. My 5th wheel is 10,500 Lbs. I have changed the air and fuel filters, but did not make a difference. Does anyone have any ideas what is happening?

**timespentsearching** · 07-01-2009, 10:57 PM

fuel filter change would be what i start with. any mods to the truck. just started happening.

manderson72 · 07-01-2009, 11:53 PM

No there are no mods. The first thing I did was a fuel and air filter change. I was in Colorado when it first happened and was told that it was because of the higher altitude, but it has done when I got home which is at sea level.

05silverado · 07-02-2009, 11:01 AM

It could be a bad fuel pressure relief valve. The reason you can't get over 2000 RPM, is that it is in limp mode for low fuel rail pressure.