On the mechanical side are you possibly pulling in oil vapors from leaking valve seals, stuck open PCV valve, or fuel vapors from a stuck open EVAP purge solenoid or other extraneous fuel source? This would be most prevalent under high vacuum.
My other guess on the tuning side would be if the computer is learning closed loop fuel adjustments under decel when the AFRs would be leanest, but don't listen to me I still have a ton to learn. Is your pedal position status going into dashpot on decel? I would imagine but can't say for sure this should tell the ECU not to learn fueling during decel. Perhaps Decipha or anyone with more knowledge than myself can say if I went off on the wrong trail.
Search found 32 matches
- 2021 Aug 31, 11:47
- Forum: GUFX - 89-93 Foxbody ECUs
- Topic: rich AFR after decel
- Replies: 3
- Views: 2249
- 2021 Aug 04, 13:35
- Forum: Speed Shop & Engine Talk
- Topic: Spark Plug Gap
- Replies: 4
- Views: 3128