A couple weeks back my boat engine cutout. I had trouble starting it and could not exceed 3k RPM so I limped back to base with maximum speed 5kts. It would not start later on.
It turned out I had several problems.
The original cutout problem was related to a weak ignition coil. It was difficult to determine that the coil was bad since it still was producing spark. I compared the spark intensity to my vehicle ignition system and the spark intensity was about 50% of what the vehicle was doing. A resistance test on the secondary of the coil showed infinity, which did not jive with good coil. I went ahead and replaced it. The motor now ran.
When I would removed the throttle body air cleaner I would hear a loud suction noise....I determine that a piece of foam was missing out of the port for the IAC. A $1.33 part resolved that problem.
Engine would sometimes cut out at idle. It turned out the IAC motor was faulty. I replace that and problem went away.
Engine would cut out at high speed. Fuel pressure was intermittently measuring 10psi. A FPR replacement brought the pressure back to 43 PSI.
My last problem...motor would miss and stumble at idle. Problem only appeared when engine was hot. I ran some injection cleaner directly to the fuel rail and it seems to now fix the problem.
I ran the engine today while at the hose for about two hours and tested it at varying speeds. It appears to be fine. I really need to test it in the water to make sure all the bugs are worked out.
It turned out I had several problems.
The original cutout problem was related to a weak ignition coil. It was difficult to determine that the coil was bad since it still was producing spark. I compared the spark intensity to my vehicle ignition system and the spark intensity was about 50% of what the vehicle was doing. A resistance test on the secondary of the coil showed infinity, which did not jive with good coil. I went ahead and replaced it. The motor now ran.
When I would removed the throttle body air cleaner I would hear a loud suction noise....I determine that a piece of foam was missing out of the port for the IAC. A $1.33 part resolved that problem.
Engine would sometimes cut out at idle. It turned out the IAC motor was faulty. I replace that and problem went away.
Engine would cut out at high speed. Fuel pressure was intermittently measuring 10psi. A FPR replacement brought the pressure back to 43 PSI.
My last problem...motor would miss and stumble at idle. Problem only appeared when engine was hot. I ran some injection cleaner directly to the fuel rail and it seems to now fix the problem.
I ran the engine today while at the hose for about two hours and tested it at varying speeds. It appears to be fine. I really need to test it in the water to make sure all the bugs are worked out.