hpfp problemss

twitch02x · Oct 5, 2013

I just loaded the hd300 and fuel on 5 and now at wot I'm only seeing 20,000 rail pressure, at idle its at 5.1?

When I'm on the throttle 75% or harder the truck has been pulling hard then just flat out falls on its face for a sec, like a east legate opened and loses all boost then when you get off throttle its OK. Check codes and nothing there. This has happened twice now. Seems like rail pressure was good with the 250 tune and fuel on 3

Any suggestions

webb06 · Oct 5, 2013

How many miles on the truck? Sounds like the HPFP can't maintain high rail pressure. The high the tune the more fuel it commands, thus why the truck loses power on the higher files.

twitch02x · Oct 5, 2013

Well today I tried it and it went to 24,600

CT9AIX · Oct 5, 2013

When was the last time the fuel filters were changed? Maybe got some crap from the bottom of the tank that really clogged them up.. or the LPFP dying out not feeing the HPFP what it needs. Try the easy stuff first.