I have a 1996 Baja Islander 19 ft. i am having problems with the engine sputtering and backing it's self down while running. Sometimes it will back down then get back to full speed or it will backfire and stall out. I checked all the filters they are fine. I am using 93 octane good gas. I put a new fuel pump in and still having the problem. I also hooked up an external tank and that didn't help and I did the same thing. Any suggestions would be greatly appreciated. Thank you for any help!!

check fuel presure even if you have a new fuel pump you could have gotton a bum one or your fuel presure regulater could be going bad. is it a efi set up??

yes it is EFI.

I apologize its not fuel injected. its a 4.3 V6 merc i believe

it does sound like a fuel prob/.

If it is an electric fuel pump I would double check all the wires and connections. If the electrical power to the pump is interupted at all that is what you will get. I had that to happen once and it turned out to be a loose battery cable of all things.

thanks for all your suggestions.