twin 502 merc engine problem idling HELP
 

Today the wife and I went to the lake , started the boat ran fine . Got on plane and away we went. We have a 95 baja 38 special twin 502 mpi's. Went to a cove hung out for about a hour then went to start the boat , started fine , went to take off and port engine lost some power and went into some sort of idle mode. Couldn't rev it or nothing, then shut down. Starboard engine still ran fine. Waited about 5 to 10 minutes port engine fired up and took off and away we went. Got to our next stop , hour later both engines fired up started to take off and port motor shut down. Tried to start , would sputter and try to turn over but could not turn over . Waited 5 min turned it over again fired up for about 3 to 5 seconds and sputtered , try to Rev to keep it running and shut down. Would not run at all just turned over. Eventually limped back to the dock with one engine . Any ideas IAC? Distributor? Anything would be greatly appreciated .

What's vapor lock ??? Never heard of it, sad to say. How do I get rid of it. This port engine does turn over slower by the way than the other

or fuel pump or distributor module or coil.

Fuel psi tester and spark tester are a man's best friend.

^^^^ this with conjunction of weak low pressure mechanical fuel pump supplying the VST.

does the fuel system have a fuel loop from pump, injectors and return line back to VST? Just trying to learn.. as that's how my Merc Optimax was node?

thanks