> > >> 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, there is a known problem with the Mazda injectors leaking on high milage vehicles.  My '86 RX-7 did this (it would flood after shutdown and be extremely hard to start) until I
     fabricated my own bleeder which cured the problem.  RB seals a kit to provide the bleed Mark and Bobby speak of above.  This is a separate issue from fuel condensation.
     Ken Powell

-> "Powell, Ken" wrote:

Paul, there is a known problem with the Mazda injectors leaking on high milage vehicles.  RB seals a kit to provide the bleed Mark and Bob speak of.  This is a separate issue from fuel condisation.
Ken Powell

Why not just put new injectors in? The Ford injectors will fit and they are
a lot cheaper than the Mazda NDs. Seems like a bandaid to deal with old
leaking injectors.

Paul Lamar
 
The Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2004 All world wide rights reserved.