Blake,
I've been working on this all weekend so I have already tried everything I
could think of. And of course, I did screw up a few things during the
first several rebuilds. I did initially manage to put in one of the valves
backwards - for the fuel inlet. Of course, the pump then pumped but no fuel
ever came out. It was then, that I went thoroughly over the Haynes
instructions.
I have tried quite a number of variations of unscrewing the diaphragm. The
pump only works over a narrow range of unscrewings - too much or too little
and the pump will hum rather than click. The latest setting, which gave me
the familiar pitches of empty and with fuel, was the only one that actually
pumped fuel, albeit shortly. And it did pump some fuel and air out the line
before it stopped.
It has occurred to me that I in reality have not fixed the initial problem.
The pump had voltage and did not pump. The same problem still exists - I
only got to see it click because it was empty of fuel. The same condition
may have existed before I removed the pump - I just figured it was bad so I
took it apart, cleaned it, and replaced the diaphragm and points. Once it
was full of fuel, it stopped pumping (again?). Thus I am inclined to
believe something like a weak pressure spring. How do I tell?
I know this pump is at least 17-18 years old and has in excess of 150k
miles, just from my ownership. And the pump could have been old then.
David
67 BGT
71 BGT
At 04:04 PM 8/6/00 -0700, yd3@nvc.net wrote:
>Dave:
>
>It appears that if there is fuel in the pump body, there is just enough more
>resistance that the diaphram doesn't move quite far enough to throw over the
>points. You could have a weak pressure spring or the diaphram is not
>stretching
>enough. If you're sure you've followed the manuals directions correctly, I
>would unscrew the diaphram one more hole counter clockwise to make sure
>that the
>points throw over.
>
>There is also the possibility that you have one of the valves in
>backwards. The
>valves don't hold air well so enough leaks past the valves with no fuel. When
>the valves are wetted with fuel they seal and the pump thinks its full. A
>quick
>test is to remove and empty the pump of fuel and try sucking from the outlet.
>You should be able to easily such air, and hear the valves chatter, but
>blowing
>will be difficult. If you can't suck any air out of the outlet, then the
>outlet
>valve is in backwards.
>
>Blake
|