my 2003 Sea Ray 340 keeps shutting off

by Ed
(Homestead)

I have a 2003 Sea Ray 340 Sundancer with twin inboard 8.1 S Mercruisers. In August was coming back from Marathon Key to Homestead (About a 78 mile ride)when I hit something below. I had to put Ethnol gas because Rec 90 was not available for the ride back. The boat sat for about a month until I was able to get the prop fixed and installed. Now the starboard engine is having issues starting and staying on. When I push the igintion switch on, no alarm sound. When I hold the switch down, alarm sounds, engine tries to start but doesnt. I started playing with the switches, alarm sounds, hold switch down and engine starts up. When she starts, she runs for a little bit, I get check fuel pump relay and few seconds to minutes later she shuts off. After going through this process a few times, was able to get her going and usually after she was warmed up and cruising no more shut offs. However now the problem is getting worse, As soon as the check fuel pump relay alert goes on, engine starts to bog down and shuts off. When the alarm did sound again, I immediately drop her down to idle throttle and then raised her back up to cruising speed. She would let me do this about three times before completely shutting off. Boat was given a tune up before all these issues began. Engine has 10 hours since tune up. I did clean contacts too. No issues with port engine.