2013 60hp 4 stroke EFI misses at higher rpm

[miichael18]

I have a 2013 60hp efi 4 stroke that I have owned since new. The problem is it had a miss that only starts around 4500rpm. Sometimes it runs great some times it misses every few seconds. Higher rpm has even more miss. Under 4500 rpm ot runs perfect all day. I was told it was probably the fuel injectors but I have cleaned them 3 times including backflushing them with hooking up power to them and activating them. I have ruled it down to a electrical problem what do you guys think it is?

I have drained tank, ran it off another tank, cleaned vst, tested high pressure fuel pump (it holds 40psi the whole time it misses and doesn't drop) new fuel filters cleaned injectors new spark plugs. Still have a intermediate miss that doesn't do it all the time and only above 4500rpm? I'm thinking coil packs? Anything else I could test?

 

[ahicks]

Locate and clean all of the ground wires?

 

[miichael18]

Locate and clean all of the ground wires?

Will check the ones I can get too. Will add the boat is stored and has been its whole life in a climate controlled garage and not in freezing or hot weather. Nothing is dry rotted or cracked up from elements