Normally I wouldn't be one to ask for help on my car as I like to figure things out myself but I am at my wits end on this one.
I have an 07 335i mt that is sitting at 102k km and is full bolt ons, so inlets, outlets, 5.5 inch intercooler. I am running a jb4 + mhd bef on stage 2 and have a consistent misfire (only cylinder 6 every time) just above 6k rpm in any gear above 2nd. Since my taking of ownership two years ago I have preemptively changed out almost every part to get ready for a single turbo sometime next year. Brand new index 12s, a new hpfp, a walbro 450 lpfp, new fuel pressure regulator, Eldor coils, ngk one step colder plugs and some more items that are likely not pertinent to the issue at hand.
With all these new components I still have problems with the hpfp taking a dump past 6k rpm. The low pressure side is fine as far as I can tell but the high pressure side abruptly drops after 6k rpm to under 1500psi or in the case of the log 1350psi. The car goes into limp mode and either displays a misfire code for cylinder 6 or it comes up with no codes at all which doesn't make it easy to pinpoint a smoking gun.
Living in Canada, I don't have access to e85 so I'm running shell 93. I figured that the hpfp would have no issues at all keeping up on pump with stock turbos but maybe I'm wrong.
Does anybody have any idea why my hpfp seemingly can't keep up?
I have an 07 335i mt that is sitting at 102k km and is full bolt ons, so inlets, outlets, 5.5 inch intercooler. I am running a jb4 + mhd bef on stage 2 and have a consistent misfire (only cylinder 6 every time) just above 6k rpm in any gear above 2nd. Since my taking of ownership two years ago I have preemptively changed out almost every part to get ready for a single turbo sometime next year. Brand new index 12s, a new hpfp, a walbro 450 lpfp, new fuel pressure regulator, Eldor coils, ngk one step colder plugs and some more items that are likely not pertinent to the issue at hand.
With all these new components I still have problems with the hpfp taking a dump past 6k rpm. The low pressure side is fine as far as I can tell but the high pressure side abruptly drops after 6k rpm to under 1500psi or in the case of the log 1350psi. The car goes into limp mode and either displays a misfire code for cylinder 6 or it comes up with no codes at all which doesn't make it easy to pinpoint a smoking gun.
Living in Canada, I don't have access to e85 so I'm running shell 93. I figured that the hpfp would have no issues at all keeping up on pump with stock turbos but maybe I'm wrong.
Does anybody have any idea why my hpfp seemingly can't keep up?
