hello gents/ladies,
I have been trying to diagnose a misfire/timing pull issue in cylinder 4. background on the car: 2018 f80 comp dct with about 55000 miles. i picked it up sept 2022. stock tune but ive been using my bm3 license to log and monitor.
the timing pull can be anywhere from -1.5 to -6. partial throttle and on tip on just before WOT it almost always exclusively pulls timing on cylinder 4. and when full throttle, timing is pulled all the way up to redline on just that cylinder. initially i thought it was a fuel issue so i have been enriching the fuel from my local gas station with about a gallon and a half of e85. timing got better overall on the other 5 cylinders but cylinder 4 timing corrections still remained. next up i changed all my plugs and coils to brand new ones. plugs are oem on stock gap .032". along with the splash of ethanol, the results is pretty much no timing pull on all cylinders except number 4. its not as bad but its there. i hooked it up to ISTA this morning and reset all adaptation. idle and throttle response improved but the corrections are still there. so now, im stumped on my next step, am i gonna have to just pony up and replace the injector next? or do a compression test? or leave it alone? worth noting that im still on stock tune and im hesitant to go bm3 stage 2 91 map if the injector is indeed faulty or on its way out or if worse case scenario my compression is low.
what do you guys think? any insight would be helpful!
logs for review:
https://www.bootmod3.net/log?id=6418...729bcb7c276e15
https://www.bootmod3.net/log?id=6418...0b43bc84223b78
https://www.bootmod3.net/log?id=6418...0b43bc84223b77