I’m running a Subaru 28hp EFI. Bought the motor new and has approx. 65 hours on it now. Has begun to give me very hard starts. It will usually start as it should when it is cold, but after the motor is warm I’m lucky to get it started. If it doesn’t start after the first several cranks I have to hold the throttle wide open and crank for approx. 20 seconds and it will maybe sputter to life. Then it runs extremely rich, blowing black smoke and smelling of fuel for first 20-30 seconds until it cleans itself up and runs as it should. If I shut it off and try to restart, I’m right back to the hard start situation I described above unless I wait and let the motor cool for some time.

I’ve been through the obvious multiple times, checking fuel lines/filter, battery charge, etc. and am pretty convinced the problem is in the fuel injection system, maybe a MAP sensor or temp. sensor or something similar. I wonder if the FI system is telling the motor it is cold and needs ‘choked’ even after the motor is warm, therefore overfueling and essentially ‘flooding’ itself.

I’m hoping someone else out there has experienced this and can steer me in the right direction to pinpoint the problem. Thanks fellas!

I would be looking for fuel dripping into intake when key is off. Hi pressure pump usually has a vent back to intake. I would look there first. Also possible injector leaking down