<VV> electric and mechanical pumps

[Sethracer at aol.com]

In a message dated 7/25/2010 11:01:51 AM Pacific Daylight Time, 
tony.underwood at cox.net writes:

Sure, some mechanical fuel pumps sometimes fail.   Most of the time, 
they do not fail.

 
I am not picking sides in this debate - but examine Tony's statement. How 
many Corviars are running their original Mechanical pump? What percentage? If 
that percentage is over 50%, then the statement is true. Now, mechanical 
pumps can fail in several other ways than leaking gas into the crankcase and 
could have been replaced for those reasons.
 
The point is that mechanical pumps - just like electric pumps - can and do 
fail to work. So they will be replaced. The only reason for the 
electric/mechanical debate was the run of mechanical pumps - now many years back - which 
allowed failed pumps to be replaced with soon-to-fail pumps. Along with 
some questionable vendor back-and-forth posturing over the years, the 
reputation of mechanical pumps took a big hit. Along with the increased availability 
of electric pumps - of all kinds - and the move of new cars to exclusively 
use electric pumps, it is only natural that a competing technology would be 
investigated. I have run both types of pumps on my cars, indeed on the two 
Corvairs in my driveway, one has a mechanical, the other electric. There is 
room in the Corvair universe for both. 
 
 
PS - Tony is right about the puffing of crankcase fumes out of the fuel 
pump vent - that usually indicates engine blowby which has overwhelmed the PCV 
system. Be sure to check out all the tubes and hoses on the car, including 
the orifice into the air-cleaner feed tube. 
 
Seth Emerson
San Jose, CA