yamaha ox66 efi stalling problem

[PAULDIDIT]

I have a 2003 yamaha ox66 efi that has a problem of stalling at idle sometimes in gear and sometime just idling at the dock. It will start right back up after stalling. Its like it sneezes once big time and stalls.
I know that sneezing usually refers to lean condition but it seems that its running a little on the rich side to me .
I've had the injectors cleaned and checked
Ive checked the fuel pressure which is good at 32 psi
I've replaced the low pressure fuel pumps and even rechecked them for being good .
Ive replaced the tps and set the voltage to spec with a DVOM after finding and open in the sensor as it was ranging up.
base idle is set at 750 RPMs.
any help would be appreciated

[rodbolt17]

lean sneeze is a condition where the A/F mix in the crankcase is so lean it detonates as the piston is moving down compressing the next air/fuel charge.
this explosion cannot exit the reeds so it tries to reverse the piston travel.
if violent enough it can shear flywheel keys and such.

have you tested O2 sensor feed back voltage?

[boscoe99]

Where are you getting your fuel pressure value from? All of the documents I have indicate that the fuel pressure specification is 35.6 psi. Low fuel pressure translates into a leaner than normal air/fuel mix.

[PAULDIDIT]

thanks guys i will look into the o2 sensor closer and the pressure regulator,.
I cleaned the o2 housing which was already pretty clean and removed the sensor and blew that out as well .
My mistake I thought the regulator pressure spec. was 32 psi .
I'm the second owner of this boat and still trying to work out the bugs, the last owner was a gas and go kind of guy if it ran it was good enough. I've been working on her for 2 years right now to get the engine and the boat back to the condition it deserves. i'm gaining all the time.
Thanks again and I'll keep you posted.

[rodbolt17]

I don't care that you cleaned anything.
IF the O2 sensor output is wrong the ECU will react.
only way to tell is simply monitor the sensor output voltage.