Paul Lamar:

On a rotary it is not a good idea to let the raw fuel drain into
the intake as it could cause hard starting and seal sticking. It
is an absolute no no in an RX8 engine as it is guaranteed it
won't start regardless if the apex seals stick or not.

Would this post-shutdown fuel seepage problem be solved by having
the fuel pumps on their own pullable circuit breaker, and having a
shutdown procedure that involves pulling that breaker while at
idle?  This would permit the fuel rail pressure to be relieved at
shutdown, making the injectors less likely to seep.  It's also very

reminiscent of how Lycosaurs are shutdown; is that good or bad? :-)

Russell Kent

Hi, Russell...unfortunately, I tried that . I did it at idle, at
2000 rpm's and at 4000 rpm's.  Still leaked.  I also installed
seperate switches for the two high pressure fuel pumps, and killed
the engine by shutting off the fuel pumps. You could hear the engine

go lean, then quit.

About 10 seconds later, the fuel drip started.  My suspicion is that

even though I shut off the fuel, there was still enough fuel coating

the insides of the long intake tubes (which ran downhill), and
slowly pooled at the throttlebody and got past the butterfly plate.

I also tried just

turning off the ignition (coils) no noticeable difference.   Paul

Conner

Yep that is what happens. Particularly if the engine is cold.

Paul Lamar

"Bobby J. Hughes" wrote:

This may be a dumb question but would the fuel still leak if the fuel
pressure is bled off quickly? I am referring to the regulator bypass
bleeder that Mark Steitle and the Egg Subi folks have installed. It
bleeds the pressure and some fuel back to the return line at all times.
This was the fix for vapor lock problems the subi folks where
experiencing with auto fuel at higher altitudes.

Bobby Hughes

It is not necessarily leakage. It is condensation inside the runners.
If it were leaking that would certainly help but what should be done
is replace the injector replaced as that is a sign it is worn and
no longer functioning properly.

People act like this condensation is some sort of huge problem.
If you are really worried about it put a hot air blast tube on
the manifold from the muffler. God knows we have plenty of heat 
from the exhaust. That will result in a slight HP penalty but is 
commonly done in cars to improve the idle.

Paul Lamar
 
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