500 efi mystery ?
 

does anyone know of a common problem with starting issues on 500 efi motors? my symptoms are very erratic,only seems to be an issue when ambient temps are above 95 degrees.port side motor will crank and fire but immediately die when oil pressures comes up.only have this problem after running and letting boat sit for 1-3 hrs.never has had any cold start issues or running shutdowns. thanks

I have been having a similar problem with my 500 EFI's. My starboard will start fine but after a couple minutes will die and will not start for at least 15 minutes. I think mine is loading up with fuel and when it dries out it will then start. I've found that if i increase the RPM's to about 1500 for 5 minutes or so it will run fine, until i shut it down and sit for a while. Does this sound familiar ? I had'nt thought about it being related to ambient temps. Maybe someone could shed some light on this.

check your iac. also have you changed the throttle blade position at all? lil thinkgs can make a diff. you may have to make sure the blades open a bit more.

There was a problem that I heard of a few years ago of a "vaporlock" on early 500EFI's something was wrong with the fuel pump or "cool fuel" system. Try searching