Int9900 cm870 isx with intermittent low fuel pressure code.....fuel pressure dropping to 50 psi intermittenly, plenty of white smoke and no throttle response...as i said it only happens sometimes...so in not thinking its the pump....any suggestions???
my gear pump did the same.
My advise to save you some gray hair, replace both the gear pump and lift pump at the same time. I went threw TRP for both the parts, both are genuine cummins parts.
Also while you are at it, might as well take the whole IFSM of and replace the dampeners behind the IFSM!.
lol while your at it.... check the fuel lines, replace those too!
It only took me 3-4 hrs my 3rd time aroun taking the IFSM of :D.
wish you the best!