Let me take a shot. Cyl#3 counts a lot of misfires. Cyl#4 counts some as well. The relative compression shows low on 3 and not great on 4 as well. Cyl#4's power stroke/Cyl#3's intake is low. Cyl#3's power stroke/Cyl#4's intake is low. This could easily mean #3... Login to read more.