Trying to figure out my 06

working on my 06 cummins 6 spd. i wanna start tuning it, but something isnt right with the truck. and im hoping someone on here might have some idea of anything else to check before i throw injectors at it. ive replaced the FCA, CP3, pressure relief valve, cam, crank, map, intake air sensors. i did an injector return test and that showed within spec.
issues i have is on a cold start on decel, the rail pressure will hang and climb then fuel knock. after 5-10 mins run idling or a couple miles of driving, it doesnt happen anymore. then the truck feels like it just lays over after 2200-2300 rpm unless you give it 75-90% throttle.

ive attached a quick data log driving around the block with my trailer on. lost the log i had without the trailer. appreciate anyone's suggestions or help.
matt

Attachment 147640

Could you share the tune?

DodgeBoy.
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Do you have a aftermarket lift pump? If so too high of low side fuel pressure can make it hard for the FCA to relax. To fix it you'd either need to adjust the FCA curve or decrease low side pressure. Also make sure your engine grounds are in good shape as well your positive cables. These trucks are getting older and people tend to leave things disconnected after being worked on, especially grounds for some reason. I deal with it daily... most issues are self inflicted.

low side fuel pressure at idle is 17 psi, at wot lowest ive seen it is 15.56 psi. i have a fass on the truck. it came from a LB7 Dmax. got the pressure spring for a dodge version from FASS. on the dmax spring it ran 12psi. the dodge version according to them has a 17 psi spring and thats the only difference.

the tune is stock with the exception of the PTO idle settings and the fuel level settings.

i will also look over ground and battery cables. ive never noticed anything weird about them, but i will go over them again cause you never know.



Attachment 147865

Have you tried unplugging your lift pump and see if that helps? I had a fass sucking air from the 90* inlet elbow that comes with red paste pre applied on it. Remove it, wire wheel that crap off and apply some teflon tape. Also for some reason I can't get the fuel systems tab to open on that file..... It clicks onto it but stays on the last tab..... Even when i reopen it while previously on that tab it just opens the tab to the left or right, systems or trans diag.... Do you have that same issue?

no i dont have that issue at all. i read it out with VCM Editor 4.8.7. and i can open all the tabs. however, i do have the same issue with the latest Beta. ill go pull it with the latest beta. and upload it here.

just read it out with the latest beta. i have the same issue. gonna submit a ticket. if you have 4.8.7 around that it should work. i dont like how they changed some of the tables which is why i havent updated it.