1996 carver 310 with dual volvo penta (ford)5.0 engines. at the beginning of the season we were having issues with the engines running rough while cruising. would get up on plane and eventually start bogging down. the engine sync gauge would go one way or the other and then eventually stall one or both of the engines while putting thru the marina. after going thru some maintenance items, cleaned the air filter, checked the plugs(ok), cap and rotor were toast replaced that. one of the coils tips was rusty and corroded replaced with an oreilly brand coil and seemed to work fine for a little while but ended up getting a DOA coil. replaced with another one and that seemed to work but then more issues started arising later on once it got warmed up and on plane again. bogging down while up on plane. at one point i was thinking there was a fuel issue because we were doing some hard banking left and right and would nearly stall but then swapped in an original coil and could not get that specific issue to repeat. i believe the coils still may be an issue and plan on replacing with motorcraft ones and still need to check the fuel filters for contaminants. had a thought that potentially the ignition control modules for each engine might be causing an issue once they get hot but i have no codes stored in the pcm. im no expert on obd1/eec diagnostics vehicles/engines. any of your help and wisdom would be much appreciated.