<VV> Re: DO VAIR CARBS GO DRY?

Larry Forman Larry at Forman.net
Tue Oct 11 01:34:09 EDT 2005


At 05:23 PM 10/9/2005 -0400, N2VZD at aol.com wrote:
>my rampy likes lots of pumping to get started after a day or so of
>inactivity.  my van starts right up (after one pump to set the chokes) 
>when left alone
>for long lengths of time...what gives?  like the old rochester quadrajet bowl
>drain syndrome?  the carbs are all late models with power circuits, same jet
>sizes etc. someday i would like to know.  meantime this winter i plan on
>building 4 new carbs identicle as possible  just to try. next it will be fuel
>pressure gauges on both also.i have seen some nice small ones at napa.
>regards, tim colson

Hi Tim,
My Greenbrier started acting like that.  It was taking longer and LONGER to 
get sufficient fuel to start.  I replaced the fuel pump and no 
change.  Finally I installed an electric fuel pump.  Only THEN did the real 
reason become obvious when fuel was PUMPED out of the flexible fuel line 
leading into the engine compartment.  Once I replaced that flexible line 
AND had the electric fuel pump did it start rapidly.  It probably would 
have if I had just replaced the flexible line.

Fast forward a year or so and the Greenbrier was getting harder to start 
once again.  Mostly when it sat for awhile but sometimes even on a quick 
run to the grocery store.  I was thinking it was the Bosch Super Coppers 
that have done good duty for awhile and I was just about to check them when 
the Greenbrier simply would not fire on a Monday AM before work.  So I 
needed to trouble shoot it quickly.  A remote starter button was attached 
and the main coil wire placed a short distance from ground.  It would fire 
about once per revolution, not good for the COIL wire.  So I thought I 
would quickly measure the positive coil wire and ensure I had the full 12 
volts when cranking the engine.  As it turned out, the 1.5 ohm Flamethrower 
was registering only three to six volts when cranking.  Clearly there was 
too little positive coil voltage when cranking.  A temporary clip lead was 
run from a 12 volt source to the coil positive and the engine started 
immediately, then the clip lead was removed.  I suspect that when I swapped 
in an engine, I somehow did not properly connect the 12 volt starting lead 
from the starter to the ignition coil.  Rather than spend time locating it, 
I ran a starter solenoid lead 12 volt source and connected a power diode 
pointing to the positive lead of the ignition coil.  This would provide 12 
volts to the coil but would not allow the coil voltage to power the starter 
solenoid.  It works like a champ.  Now I just turn on the electric fuel 
pump for a second or two and then start the engine and it starts in under a 
second every time.

Total time to trouble shoot the missing 12 volts to the ignition coil was 
about 5 minutes.  It helps to have the tools right there.  I did not even 
need to lift the engine cover, and I was on my way.
--Larry



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