INDICATORS ON TOYOTA 4A GE YOU SHOULD KNOW

I read through over the internet that when they aren't effectively synced it may cause rich operating, backfiring and vibrations. Possibly I am wondering the wrong way but when they wouldn't be synced then the fuel/air mixture can be various wouldn't it?I purchased my MRS 3sgte back in 2020. Parker from NW Motor s named me and told me I used to be