[Geico266]

Interesting. I installed, but rarely use, the purge valve feature that came with my AP fuel injection system. Do you believe running cool fuel through the system (albeit not through the fuel injection lines) would help/resolve the issue?

Absolutely. Throttle wide open, mixture full rich, purge value open, fuel selector to left tank, turn boost pump on for 45 seconds. This allows cool fuel to circulate through the system and back into a tank. HOWEVER, this depends entirely on how your fuel system was pumbed. Check it out so you know what is happening.

I agree with Frank. The rough idle when hot is fairly normal with FI.

IMHO you need a cooling blast tube to the FP.

Do you have electronic ignitions?

 

[Dean Pichon]

Absolutely. Throttle wide open, mixture full rich, purge value open, fuel selector to left tank, turn boost pump on for 45 seconds. This allows cool fuel to circulate through the system and back into a tank. HOWEVER, this depends entirely on how your fuel system was pumbed. Check it out so you know what is happening.

I agree with Frank. The rough idle when hot is fairly normal with FI.

IMHO you need a cooling blast tube to the FP.

Do you have electronic ignitions?

Thanks for the input. I will try it this weekend. My system is plumbed as you describe. I have Lasar electronic ignition, but do not (yet!) have a blast tube to the pump.

 

[RV6ARoger]

Check my story about engine burping. Might give some insight.

I posted a similar situation and it turned out to be the fuel pump, floating, due to a weak fuel pump actuator arm. At high RPM, it would not provide adequate fuel flow, but at other times it was OK. See my post, responses, and what the resolution was. Who knows, it might help.
Roger.

Great info guys thanks.

I have been running 91 Octane mogas & 100LL mix, it should be around 50-50. The pump has 200 hours on it and is 2 years old. The problem showed up after I leveled off and was deceasing airspeed to do some stalls & slow flight so I'm leaning towards vapour lock also.

Someone asked what the temp of the fuel was. It was 82F. I actually took the temp of it after I landed. The plane was in a hanger all day, only in the sun during start up and flight.

If I wanted to test things one at a time I would, but I just don't want to take a chance so I'm replacing the fuel pump, installing a fuel pump shroud (a hanger buddy gave me one) & blast tubes and install additional louvers. Over kill maybe, but..............