<VV> Fuel Pump Woes

Tony Underwood tony.underwood at cox.net
Mon Sep 6 19:36:06 EDT 2010


At 02:59 PM 9/6/2010, Bill H. wrote:
> 
>B"H
>
>Hi everone!  Best wishes for a happy Labor Day!
>
>Well, I finally got bitten by the nasty fuel pump bug that seems to 
>making the
>rounds again.  I've been through 3 stock-style
>
>fuel pumps over the last couple of months, yesterday the raw gas smell was so
>bad in the car that the wife threw up in the car!  On the way
>
>home from a nice dinner at a restaurant for my b'day.  When I checked the
>engine, I saw the telltale puffs of smoke coming from the (new) pump.


Smoke??    How is smoke coming from the pump?



>Got one more spare that I bought last month from Clark's.  It has 
>hex hold-down
>bolts instead of slotted screws.


Sounds like the current crop of pumps available these days from 
Airtex, see nothing wrong with them, correct materials in the 
diaphragms etc.


>  I'll give that one a shot, but I'm hearing
>some stories of those being just as bad.


...don't believe everything you hear, especially about the "inherent" 
badness of mechanical Corvair fuel pumps.


>Anyway, before she makes me get rid of the Monza, I'd like to know:
>
>1. if anyone understands how to fix those defective fuel pumps?


...I've rebuilt one or two...   ;)



>I read the
>recent CORSA Communique article on it, but I don't understand how you're
>supposed to mash the metal to keep the diaphrgm in place.


??   All you need to do to a *Good* (read: correctly assembled) 
mechanical pump is MAYBE snug up the screws a time or two as the pump 
settles in during regular running.


>2.  Is there any way of identifying a defective fuel pump by the tag?


No.  The tag number is the same for all later (post-'61) pumps.   The 
bogus pumps are identified by looking at the sides of the diaphragms 
that protrude out the sides of the pump.   The CORRECT pumps have 
fiber reinforcements in ALL the diaphragms.   Some use rubber 
diaphragms with no fiber reinforcement and they WILL FAIL in short order.

I'd thought all those pumps would have self-terminated and been 
weeded out of the food chain my now... but maybe not.

Do NOT listen to ANY sales guy who insists that the plain rubber 
gasket pumps will be "just fine".   It's BS.   Go elsewhere.   Don't 
buy ANY pump that does not have ALL fiber reinforced 
gaskets.   Seriously, this is important.


Also, this bogus diaphragm material that got used by some 
rebuilder/manufacturers was NOT restricted to just Corvair 
pumps.   It ended up in other reman'ed and repro pumps as 
well.  We're not the only ones who complain about replacement leaky 
fuel pumps.   I know a guy with an older Cadillac who went through 3 
pumps before he finally found an original manufacturer's part with 
the right diaphragm material.   Likewise a fuel pump that was bought 
for my brother's "Fiat 127" (don't wanna say Yugo in here for fear of 
ridicule) which used that SAME crappy rubber.  That pump was returned 
for credit, the original, which was disassemble'able, got taken apart 
and fixed on my bench, afterwards, no more problems.

I used a piece of the same material I use on 'Vair pumps.   ;)



>3.  Also, if I'm forced to, can anyone recommend a reasonably-priced electric
>fuel pump along with any other suggestions for retrofitting such a pump
>to a 69?


The *correct* mechanical fuel pump will work just fine.   There is no 
need to go with an electric pump unless you are dead-set on it, which 
also carries its own idiosyncrasies.

And YES electric pumps fail too.


>If I can't stop the car from those nasty smells, I'm afraid I"m gonna have to
>put her up for sale, and soon!


Advance Store and Auto Zone (at least they do around here, just 
recently bought two) sell Airtex pumps and you can inspect them 
before you buy them.


Don't forget to snug up the screws before installing a new pump AND a 
few days after running a freshly installed pump to settle/seat the 
diaphragms which *will* take a "set" once they've heat-cycled a few 
times.   This is normal and to be expected, and once the pump settles 
it should be good for the duration... as in for years.     Just snug 
them, no need to twist them until they scream for mercy.

But if your pumps is misbehaving, I'd check those diaphragms.  Now.

This topic has been discussed at length several times, including 
lately.   AGAIN:   I have a JPG photo demonstrating the differences 
between a bogus pump's diaphragms and the good pump's diaphragms for 
ANYbody who wants one.






tony.. 


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