<VV> fuel pump issue

[Garry Parsley]

Thanks Timothy,

Everything inside the rear housing was in good shape, with the exception of 
the eccentric, which appeared rough, and slightly discolored. The spacer and 
gear were both good. I've not tried the screwdriver in the rod trick yet, 
but will this weekend. I'd not heard of the valves in the pump needing to be 
staked, but will check that out also. So far I've been doing this alone, and 
have not been able to check anything while cranking the engine. I'll get a 
helper this weekend. Any thoughts on the shaft length? Other than putting 
additional pressure on the diaphragm and push rod, I can't understand why 
this might make it not pump.

Garry

-----Original Message----- 
From: shortle
Sent: Wednesday, November 12, 2014 9:40 PM
To: Garry Parsley ; virtualvairs at corvair.org
Subject: Re:  fuel pump issue




-----Original Message-----
>From: Garry Parsley via VirtualVairs <virtualvairs at corvair.org>
>Sent: Nov 12, 2014 4:25 PM
>To: virtualvairs at corvair.org
>Subject: <VV> fuel pump issue
>
>Hey gang,
>
>After 8 months of work I’m finally at the start it and adjust stage on my 
>66 Monza, but am still having an issue. When I put a little gas in each 
>carb, it fires right up, then dies. A definite lack of fuel issue. The 
>original pump was leaking, so I ordered a new one. While waiting for it, I 
>read the tech guide articles about the wrong length stem coming out of the 
>pump on the newer versions.  The original pump was 1/4” long, so I checked 
>the push rod. It wouldn’t come out, so I ended up removing the rear 
>housing, and found the end of the rod mangled. The “too long” shaft now 
>made sense. Have now replaced the sending unit, hoses, fuel pump, push rod, 
>eccentric. The new pump’s shaft was 9/32” long, so I cut it down to 7/32” 
>but it hasn’t helped. I’ve verified fuel to the pump, but when I crack the 
>lines at the carbs and crank it – dry. My question is – is it possible the 
>rod in the pump is still too long at 7/32” sticking out? Could this be 
>keeping the diaphragms from doing their job?  I didn’t want to risk cutting 
>too much off, but will listen to all suggestions. I fear I may have 
>tunnel-vision at this point, and would appreciate some input.
>
>Garry parsley
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Hi Garry, This sounds interesting. One time I could not get a new pump to 
work and what I found was my eccentric was not tight on the crankshaft. When 
I cranked the engine over with a phillips screwdriver in the center of the 
rod I could not feel the rod going up and down. So I removed the rear cover 
and found the spacer on the crankshaft was cracked/broken which allowed the 
eccentric to "wobble" but not push the fuel pump rod. As I recall a bunch of 
stuff was mangled in there including the eccentric, spacer, distributor 
drive gear (brass), the woodruff key,push rod, etc.  I never forgot this. I 
hope this is helpful. Another thing, did you stake the valves in the new 
pump? I have heard of them not being tight.
Timothy Shortle in Durango Colorado 81301