1998 Mercruiser 5.0 EFI backfiring

[Newboater5.0EFI]

The engine backfires on acceleration. Then runs perfectly fine. Slow down fine. Give throttle and again backfires before getting to plane. Then runs fine again. Slight rough idle when warm. No stalling. Cap rotor plugs and wires? Runs at normal temp. Can anyone help with this?

 

[Bt Doctur]

cap,rotor, plugs and plug wires for a start, then fuel pressure at the rail,idle and under load

 

[Newboater5.0EFI]

Thank you.