502mpi coughs, then dies
 

I have a 93 Sunsation with a 96' 502mpi. Went out yesterday for the first time to the lake. After 5 hours or so on the water, engine started acting up. It would cough a little and then die. After letting it sit for a minute or so, it would fire back up. It did this three times, took a while to get back to the launch. Was running fine all day up to this point. It almost seemed like it was starving for fuel. I know there is a fuel filter so that would be the easy choice. Any other ideas? Any help is appreciated.
Thanks
Sean

Re: 502mpi coughs, then dies
 

SARS ???

Seriously, it could be a number of things:

Fuel filter (as you mentioned)
Bad gas (although it probably would not keep re-starting)
Bad fuel pressure regulator
Clogged flame arrestor (has anyone actually ever had this happen?)

The list goes on, but I'll let more qualified individuals take over from here.

Is there an easy way to drain the tank? I am pretty sure there isn't but I figured I would ask

Sean,
I had the identical problem late last fall and it was in the fuel system. My boat had the VST tank....anyway, if you take the VST tank apart there is a screen/filter that slips on before the high pressure pump gets the fuel....mine was about 95% clogged which would give the engine enough fuel to fire and even idle for a minute or so.....then when trying to take off the pump can't get enough fuel to it so the motor starves and dies. There are also screens in front of each injector to final filter the fuel before hitting the injectors...I took my fuel rail apart and cleaned those as well...they were not as bad. If you want to know more, take a look at the picture HERE

Drop me an email or PM if you have questions and I can try to walk you through it.