10-25-2011, 12:40 PM
Join Date: Feb 2010
A weak CP3?
Hey all, last week my truck took extra long to crank and start (no abnormal conditions) so me and a buddie did some data logging with efi live and found out I've got a low rail pressure issue, we have it programmed to make about 23'500 psi and Im only getting about 14'500 psi under full throttle, I have never swapped a CP3, any opinions would be appreciated, haven't done too much looking into it yet because my truck still drives, runs fine, just a loss of power at wot, any other ways to test and know for sure its the pump and not just a regulator, I read something somewhere a long time ago about a test gm does that you can do with efi live ramping up rail pressure to some magic 165 number or something (i dont remember exactly) to see if it holds or the pump is working properly. Let me know what you think.
2001 GMC 2500HD, 02 motor, 5 inch custom exhaust, custom intake, DiabloSport Predator, EFI live, 33' Fierce MT's, Glow shift gauges, touchscreen head unit with tv tuner, Spare wheels with studded tires (for fun on the ice).