Die's and hard start or no start intermittently
 

96 Mariah 5.7 started dying or cutting out when in rough (ish) water also noticed when turning or taking off oil light would flicker. Problem with dying kept getting worse even in calmer waters. Now it wont start but will turn over. Is there a flip/tilt/impact switch that could be causing this or am I just hoping its something as simple as that? Its my B-I-L's boat and we are trying to figure out what is wrong Have checked most electrical connections but not everything yet.

Any Ideas?

Re: Die's and hard start or no start intermittently
 

Check the fuses to see if any are loose in their socket. Mine had a few loose ones that were intermittent so I replaced both fuse blocks.

Re: Die's and hard start or no start intermittently
 

Start with the basics, check fuel pressure with a gauge and check for power to the ignition coil and ecu. If missing any of the above work backward to find your issue.

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Re: Die's and hard start or no start intermittently
 

My first thought is the fuel pump/

Re: Die's and hard start or no start intermittently
 

I had a similar issue and after educating myself on boat mechanics, I found that the fuel pump has many different things running through it and to it. For example, a bad oil pressure switch could shut down the fuel pump. A bad alternator could shut down the fuel pump. A clogged fuel filter could be keeping gas from the fuel pump. A clogged fuel line could be keeping fuel from getting to the carb from fuel pump. Not to mention the electric choke also runs through the alternator/oil pressure switch...

LOL, it is a tangled mess so I replaced everything and now my boat runs like a champ.