Rail pressure can't keep up and P0148
 

Was driving today and went to pass as it was accelerating it felt like my Edge was defueling. Played with it flooring it while watching my gauges. Watched the rail pressure and watched it drop as it is it studdard. Then my check engine light came on with the P0148. No other issues accept 80% throttle or more stuttering. Also my rail pressure jumps to 25k for a second or 2 when I let out of it. Without having the tools to test it properly it sounds like FCA or lift pump to me. Anyone had anything similar?

I recently replaced my FCA - I was throwing same code but sometimes when I would go WOT rail pressure wouldn't go over 14k - I tested it as suggested which is run truck- unplug FCA- it should peg your RP gauge- it will sound like $h!+ when you unplug it so just leave it unplugged long enough to read gauge then plug it back in. Mine actually tested fine doing that but was still the culprit. Buy from Cummins not the dealer! Be SUPER CAREFUL not to strip torq screws! There's many threades in what I nightmare these can be....my expierence sucked and ended up using a T30 to finally get them out! Since replacing no code- running better and RP at idle is much more steady- it would fluctuate from 7.5-9k before now it is 7.8-8.2k - I have about 235k on mine btw

Thank you. Will try.

Also, don't rule out the Fuel Pressure Sensor, as they have a tendency to fail.:pca1:

It was the FCA. Got it from Cummins for $120. Swapped it out in 20 min. WOT status rail pressure stays at 18k. Thank you all.