2006 Outback - Starting problems - losing prime overnight?
My '06 OB has the 310hp Carb engine. This started when I pulled the boat out of storage last season. I'm having problems starting after the boat sits awhile, usually overnight. I've done quite a bit of trouble shooting. In a nutshell, after the boat sits I have trouble getting the engine to start and keep running. If I get it started, there's a good chance it's only going to run for a minute or two before it runs out of gas. The fuel between the fuel pump and the one-way check valve over the fuel tank will be completely dry when it quits. If I remove the hose from the one-way check valve over the tank, pour some gas in the line to re-prime it, reconnect the fuel line, the boat will fire right up and run all day. Shutting the boat down for a few hours is no problem, she'll start back up. But if it sits overnight, it's like the only gas the engine can pull is in the fuel line (or maybe there none there at all, not sure).
Here's where I am with troubleshooting:
Replaced the one-way check valve above the fuel tank - I thought it might be sticking and not letting fuel through. Or maybe it was letting fuel drain back into tank. Honestly it looked fine and changing it didn't help.
I don't suspect a clogged vent (i.e. vacuum in the tank when the motor starts pulling gas) otherwise the engine would be cutting out all the time, especially under high power.
No evidence of fuel leaks in the fuel line.
The hose and screen into the tank are clean (again this would affect operation all the time).
The fuel pump works. You can hear it running when the engine is running. I've also hot wired it to the battery just to make sure it was working.
Once again, if I prime the line manually after it decides not to start or cuts out after starting, it will run all day, no problems. It never happens unless the boat has been sitting for some time.
Questions about the fuel pump. Is the pump suppose to prime the line when you first turn the key? I don't think I hear it doing that if it's suppose to. Its definitely running when the engine is. Can the pump prime the line if it's just pulling air? In other words, will the pump prime the line if the fuel is indeed draining back into the tank? Maybe the pump is just weak. I'm leaning toward replacing it. Any help or ideas would be appreciated. Thanks.
