Perfectly normal... but you can fix it. First of all, you want to make sure
that your points are clean and properly adjusted. The following mesage was
an earlier post of mine so I'll save some typing and let you read on. Just a
note for after you read below: you adjust the points by rotating the
diaphram and when properly adjusted it will work reliably. The pump normally
will stop pumping when presure has been built up. If you have any questions
about it email direct creichle@nsc.msmail.miami.edu
-------
I know what this is thanks to the help of fellow list members. I too went
through SU fuel pumps until someone tipped me off to the adjustment of the
diaphram post that connects to the sping plate thingy ( good description I
know )
This is the deal. Someone told me ( sorry for not giving proper credit )
that the diaphram adjustment is sometimes not done properly when they are
assembled or in my case, the rubber shrinks and the diaphram is too taught.
When the diaphram is pulled up to suck gas into the chamber, the post (which
looks like a long nail with a threaded end) flips the points to the off
position. When you look at the points you will notice that they are spring
loaded and snap closed and open. The problem in my case was that the
diaphram was too tight and would not allow the post to be pulled up high
enough to flip the points to the off position. Normally,once in the off
position the post is released by the coil and the diaphram presurises the
gas pumping it through the valves. When the diaphram is at it's lowest
position, it snaps the points back to on and more gas is drawn into the
chamber.
In my case, I removed the pump and unscrewed it with the intentions of
rotating the diaphram one hole to the left to adjust the post so that it
would come up high enough to flip the points to off. What I found when I
opened it was that the diaphram was really tight and just didn't have the
range of motion to both flip the points off and on. It was still stuck to
the coil side of the pump so I was able to try to actuate it manually. I
peeled the diaphram off and then (leaving it in the same position) screwed
it back togather and have not had a problem since. Peeling it off allowed
the diaphram to realign on the screw holes normally, not being stretched.
Either you have to adjust it by rotating the diaphram or it may be just too
tight like mine was. I bet I could have said this all in about 4 sentences.
Sorry about the length for all of you that made it this far.
Christopher Reichle
----------
From: mgs-owner
To: mgs
Subject: Fuel Pump
Date: Tuesday,February 18,1997 10:12AM
To List:
Is it normal for Lucas Fuel Pumps
to stop for no apparent reason,
then to tap on them to get them
going again.
These pumps are starting to make me feel
like they are very unreliable.
I have seen threads about other ideas
for fuel pumps along with appropriate
pressure amounts. Can someone recomend
the correct amounts??
History:
67 B, fuel tank recently cleaned, eteched
and sludged or sealed.
Thanks for all help.
Tom Wagner
67 MGB
|