The Mariah Owners Club - New member: problems cold starting boat

Good Afternoon Everyone,

First off, thanks to all of you who take the time to post. Based on your thoughts, I've been able to test several possible causes of my problem, I just haven't been able to solve it yet.

The boat is a 1996 Shabah 180 4.3 LX limited edition. I've used the boat about 30 times this season, and started having problems cold starting the boat about a month or two ago. At first the problem was minor. On cold starts it would turn over fine but not fire. I would crank it for a few seconds at a time, and after 5 or 10 minutes it would start and then start and run perfectly all day long. More recently, if the boat sits for more than a few days it won't start at all. I've confirmed that ignition and compression are fine, fuel filter and separator are new, tank was recently cleaned and the gas is new. To get it started now I have to run 12 volts directly to the fuel pump. After "jump starting" the pump and letting it run for about 10 seconds on a secondary power source, I plug the pump back in and the boat starts right up. Once started it runs nearly perfectly from idle to WOT all day long. I say nearly perfectly because it does have one other minor hiccup. Once the boat starts, I warm it up, idle out of the marina, hit open water and go to WOT. It runs at WOT for about 1-2 minutes then just dies like someone turned the key off. It immediately refires and runs perfectly the rest of the day.

I've confirmed that the fuel pump is getting 12 volts from the starter during cranking, and I've confirmed that the oil pressure switch is functioning correctly and providing 12 volts to the fuel pump once pressure comes up.

Obviously, if I can run at WOT all day long the fuel pump is working, but I'm concerned that I may have an intermittent pump failure when it's cold. Before I go and spend $200+ on a new pump I'd like to see if you all have any other thoughts on what might be causing my starting problem.

Thanks,

steveog17