weird fuel pressure issues

razorryan10

Member
Feb 18, 2019
34
0
6
canada
truck has issue with fuel pressure when it warms up
in my tune im commanding 60mpa 600-800 rpm but when i datalog it i only see 41-42mpa for desired when cold and as it warms up desired pressure lowers 1 mpa all the way the down to 30mpa and stays there runs fine just not the fuel pressure im telling it to be
just put 2 new fuel regs on it hoping by chance it would fix but nope,
is there something in the tune that would cause desired pressure to drop lower then what is commanding, or could it be 1 or both pumps returning to much fuel they are the last thing i can change or check and they are wore out for sure being one has 450,000kms on it lol
 

2004LB7

Well-known member
Dec 15, 2010
6,969
2,137
113
Norcal
You might need to use the pressure compensation tables to get the idle pressure up that high. There is likely missing tables that we don't have that override the idle pressure. But the compensation tables can fix that
 

razorryan10

Member
Feb 18, 2019
34
0
6
canada
just took a look at b1012 and was still set to low at temps of engine so ill load the adjustments in a day or two when i get back too it and hopefully that is it
 

darkness

Well-known member
Jul 15, 2009
1,315
379
83
48
vegas
Yup, have to adjust the idle pressure table. I just went thru the same thing after changing the injectors on my Kodiak. Couldn’t figure out why idle pressure wasn’t changing with tune changes. Then I dug a little deeper.