I am having a problem I have a 1998 502mpi slightly built to a 509. The issue I am having is once engine is at operating temp I go and shut it down but when you try to restart all it does is cranks thats issue 1. Second issue now is the engine shop that built it said the injectors are dirty possilbly so I took them in they cleaned them. I put everything back together the boat ran for 90 seconds died out and wont start? Any Suggestions
Its getting fuel and it has ignition also no VST
Thanks

Do you have a low pressure sea pump mounted fuel pump ?

Issue 1 sounds like vapor lock, I believe that year omiited the mechanical pump, there is a service bulliten out on this

Issue 2, I know you have done this, but go through everything you took apart.

The old addage, the first thing to check is the last thing you messed with.

Where in Il are you?

Thanks for the post and help I found the issue not fully charged batteries and off one or three teeth on distbutor.

I am located up by chain o lakes
thanks

My engine and ecu was done by ateco engine in waukegan il