N54 Single Turbo Breaking Up

[e92_garrettz]

Morning,
I have a single turbo n54 finally got it up and running idling smooths no misfiring until it creeps up boost around 2.5k rpm the car starts breaking up really bad. I found out that the car is running too lean from what I seen. I've talked to my tuner and he believes it the injectors will need to be replace.

I did checked the injectors few months ago and there was no symptoms, let alone the car haven't start up for few months as well so it can't be the injectors if it wasn't start up for awhile? Should I still check it again by pulling plugs out or remove injectors and hang on the rail pressure to crank test it?

Car setup: I am running standalone fuel cell, with dual 450lpfp, with external fuel regulator and 750cc port injection. The car should be making conserve around 600-650whp on 93 pump gas.

Please see attached 3 logs for idling and 2 pulls one one of each logs.

Idling:

datazap.me | e92_garrettz | Idling

datazap.me

1st pull:

datazap.me | e92_garrettz | 1ST PULL (BREAKING UP 2K RPM)

datazap.me

2nd pull:

datazap.me | e92_garrettz | 2ND PULL (BREAKING UP)

datazap.me

 

[ktb_e92]

Did you just install a single turbo setup when this started happening? I'd just make sure you have your O2 setup properly done, especially if running single bank fueling with a 3 or 4-port Mac solenoid. The bank 1 upstream (black wire) has to be the one used as your O2 source in the bung on your downpipe that's a couple inches away from the turbine v-band, not the bank 2 upstream (gray wire.) Otherwise, maybe check the operation of that fuel pressure regulator since I can definitely see your fueling getting pretty erratic when it breaks up. I doubt it's your injectors if you recently serviced them and verified there are no leaks...you'd usually be able to tell on a cold & warm start if they're acting up.