Surge

[burdawg1972]

I have a 2002 GMC Duramax. It surges at idle and has given codes for low fuel rail pressure and low voltage. What could it be? Duramax is new to me I am an old Cummins mechanic. Give ma an 855 and I an on it ! The computer age of diesels is here and frustrating to us old dogs:mad:

[More Power]

First step.... Change the fuel filter. A plugged fuel filter can affect rail pressures.

Then, I'd look at commanded & actual rail pressures using a tech II scan tool if the problem continues.

Jim

[burdawg1972]

I have replaced the filter, also have replaced the water sensor on the filter. I noticed the surge and thats when I replaced those things. I also should mention when it gives that code almost instantly it goes into limp mode and will not go over 2000 rpm's and a bunch of white smoke.:confused:

[jbplock]

The white smoke and codes for low fuel rail pressure are classic symptoms of injector failure with high return rates. If so it would qualify for the 7 year/200kmi injector special policy warranty.

see the following link for more info ..
http://www.thedieselpage.com/duramax/lb7injectorwarranty.htm

[burdawg1972]

The white smoke and codes for low fuel rail pressure are classic symptoms of injector failure with high return rates. If so it would qualify for the 7 year/200kmi injector special policy warranty.

see the following link for more info ..
http://www.thedieselpage.com/duramax/lb7injectorwarranty.htm
Thank you for the info. I am currently deployed to Iraq, so I will have my uncle take it to the dealer. I will be home on R&R in a few months and I miss my truck! Is there any special info I need to give him to take it to the dealer? Thanks again.