Hi fellas,
I need some help trying to figure out a misfire in cylinder 4. But first let me say all that's happened/been replaced in the last week.
Car: 2012 x3 35i xdrive build date 3/12
-Last week CEL came on for low fuel pressure and random misfire. The car was bucking and jerking, would die out a few times, and you'd instantly smell raw fuel at the exhaust after start up. We determined that the high pressure fuel pump to be the culprit and replaced it with a BMW one. A little over $1k
-After replacement, it would hesitate (but still drivable) then CEL came on for cylinder 2 misfire. Found that the injector was bad, so we replaced that.
-After replacement of the injector, car STILL missed and CEL came on for cylinder 2 misfire again. This time the spark plug was fouled, probably from driving a bit with the bad injector. So then we decided to change ALL 6 plugs.
-Still missed and decided to clean the intake valves with walnut blasting since I have access to one, and nothing.
-After replacement of all 6 plugs, car STILL missed but now just on cylinder 6. So then we decided to replace ALL of the injectors...
-And car STILL misses, throwing a code for cylinder 5 misfire
Recap: Car has brand new oem high pressure fuel pump, 6 new oem plugs, cleaned intake valves, and 6 new oem injectors. I haven't replaced the coils yet because all 6 have been replaced about 6k miles ago, and we've been swapping them out to rule out the above problems.
Does anyone have any ideas on what to look at next?
