why do the fuel pumps go out on 6.5 [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: why do the fuel pumps go out on 6.5


big rig
01-15-2004, 12:19 PM
I herd alot of people are mad at GM for that.http://www.dieselplace.com/forum/smileys/Confused.gif

a64pilot
01-16-2004, 09:45 PM
Yeah, on my 6.5 the failure of the lift pump wouldn't be detected until after it caused problems with the injection pump. $$$

Turbine Doc
01-19-2004, 02:26 PM
I'm not a GM tech but have seen lots of message traffic on these. plus went thru a failure of my own, and helped others diagnose it. Crappy fuel and lift pump power failure being misdiagnosed as bad pump common denominator.


I have no quantative data to support this, but from my experience trashy fuel, and loss of power especially on earlier non PCM controlled via OPS causes most fuel problems on the 6.5.


Install relay power to pump and filter fuel prior to pump solves majority pump problems IMHO.


Vac gage on filt and press gage monitoring fuel to IP also beneficialEdited by: Turbine Doc