<VV> Electronic fuel pumps

[Craig Nicol]

Chris wrote: <snip>
This is a different issue and topic for me. I have only experienced the
likes of stock mechanical fuel pumps on Corvairs. This new Corvair I have,
had an electronic pump installed. My basic understanding is that its a
device that is in the fuel tank, run some power to it and remove and cap off
the mechanical one.
So, shes not starting (after fixing the loose bolts on the flex plate) she
is turning over, I have good battery power, good spark (she does fire) but I
think I'm having a fuel delivery problem, doesn't stay lit.
If I were to assume a non-corvair mechanic installed the pump prior to my
ownership (not that it matters), I am looking at the return line coming into
the engine compartment and its capped of with a bolt and hose clamp.

First, is this OK to do? or is there a problem being created by this
technique (like a pressure/vacuum) that a mechanical fuel pump might depend
on? <unsnip>

Craig replies:
Your "electronic" pump (Electric really) may be in the tank or, more
commonly next to the tank outlet at the front of the tunnel. 

Capping the return line was not necessary and may cause some hot-restart
headaches. The return line relieves fuel pressure in the lines. When the car
heat soaks, some fuel boils in the carb and enters the engine. If there's
residual fuel pressure in the lines, the boiled fuel is replaced in the
carb. The process repeats until the pressure is gone or the engine cools
sufficiently to not boil any more fuel. With pressure in the line, lots more
fuel boils and enters the engine, creating a nearly flooded engine that's
more difficult to start. Also, when running, the return line insures that
the fuel is cool, reducing the possibility of vapor lock (boiling) in the
lines. 

Next- Carbureted cars require application of throttle to start. 
Cold start: poke the gas pedal once to set the choke and once more
(maybe)for some extra fuel. Once cranking, you might have to poke it a
couple more times to get it to fire.  This is normal except for the
EXCEPTIONAL car. 

Hot restart requires NO POKE; instead hold the pedal at about 1/2 throttle.
This info is in the owner's manual too.

Please remember to sign your posts so everyone knows who's "talking"; there
are about 1000 VV readers and it's really difficult to keep the threads
straight w/o signatures. Thanks!

HTH, Craig Nicol

No virus found in this outgoing message.
Checked by AVG. 
Version: 7.5.524 / Virus Database: 269.23.0/1381 - Release Date: 4/16/2008
9:34 AM