George Lendich wrote:

Paul,
Remember the discussions on returnless fuel systems,
have a look at:-
http://www.delphiauto.com/pdf/eandepdfs/Fuel/NewElectronic.pdf
George (down under)

Jeff Spitzer wrote:

No mention of how to manage boiling of the fuel in the lines for hot
restarts.  I wonder....

Russell Kent wrote:

I'll go out on a limb and reveal some of my ignorance...
I thought hot starts was an issue for non-pressurized fuel systems
(carburated).  I don't see how fuel boiling in the cowling area of the
fuel lines is an issue for a tank-mounted fuel pump.  [Other than the
potential for a lengthy cranking, that is.]  Can you elaborate?

Russell Kent

tommayer wrote:

Question:  if a return line on an injection system is necessary to avoid hot
starts, why is it no harder to start a hot injected Lyc--neither the Rivera
nor Bendix system has a return line--than an injected Cont, which does have
a return line?  And,  if I remember right,  pressure carbs, which do have
return lines, are worse than either.

Difficulty in hot starting injected Lycs is legendary & it ain't the
urban variety.

That said, I doubt that the problems are caused by boiling fuel, since
the best technique on the 2 I've owned was mixture at idle cutoff, full
throttle. Crank until it fires, then quickly swap lever positions:
mixture to full rich & throttle to idle. This implies flooding when hot,
not boiling fuel & vapor lock.

Someone mentioned moving the pressure regulator bypass from the injector
block to just downstream from the pump. If you do this, you lose
pressure regulation at the injectors. It will take some finite amout of
time after an open injector depletes some fuel & pressure for the
regulator at the other end of the fuel line to see the change & react.
It will take a finite amount of time for the fuel which is not moving in
the line to get moving again toward the injectors. Some injectors might
tolerate this with no problems, others probably won't.

Charlie

 
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