'98 pre2200iwt: Ignition sound repeats, and boat won't start sometimes

[benmcmahon]

Hello friends,

I own a 98 Tige Pre2200 with Mercruiser Mag MPI EFI. There was always a sound when I turned the key to the ignition "on" position, but not started it. It happened every time. It sounded like some kind of pump. Today on the water, the boat wouldn't start randomly after running fine all day. It turned over just fine, but no ignition. While the key was on that "on" position I heard the sound a few times randomly, whereas I've never heard it before unless initially turning the key to "on" position. Then, after a few minutes of trying, it started. Did not have an issue again.

What was that sound, and why did it happen more than once, if it only is supposed to happen when key is turned?
And would that be related to the boat turning over but not starting? Fuel issue?

Thanks for any info!
Ben

[TeamAllen]

From your description, it sounds like the electronic fuel pump. It might be possible you are experiencing vapor lock in the fuel line or possibly a failing fuel pump. Were you pulling a rider or cruising for a distance just before you stopped and turned the engine off? Where are you located?
Vapor lock is occurring more frequently in our boats since ethanol was introduced in our gasoline.

[ajnesbitt]

Do you have perfect pass?

[benmcmahon]

Hi,

I'm located in NH. It's been very hot this week.
We pulled a rider one hour prior, but had been sitting for an hour. Do you know what that sound is when the key is turned to "on" position? It sounds like a buzzing from the engine compartment. That was normal. But when this issue was occuring, the sound happened randomly a few times within 30 seconds. That has never happened before. Is that sound the fuel pump priming or something? If so, I wonder if it's faulty wiring or fuel pump?

Ben

[TeamAllen]

I am pretty sure the noise you are describing is the fuel pump. And heat is what brings on the vapor lock. There are a few remedies to help reduce the chances of it occurring. If you are just experiencing an unusual heatwave these tricks might get you through until it cools back down? Run the exhaust fan the entire time to keep airflow through the engine compartment. Add Sta-Bil Marine stabilizer to your fuel. Let the boat idle for a few minutes after pulling a rider/cruising and before shutting it off. If it still occurs while you're on the water you can put a cool wet rag or squirt water on the fuel lines to cool it back down.

The permanent remedy is a $400 Mercruiser kit. I'm on my phone or I would link you to one of the previous threads. Maybe try searching vapor lock on this forum.

[TeamAllen]

Here is the link to Mercruiser's TSB on Vapor Lock.
http://www.boatfix.com/merc/Bullet/99/99_07.pdf