William M. Gilroy wrote:
>
> I have a 1977 Midget with a Zenith Stromberg (ZS) carburetor and an automatic
> water choke. The carburetor was rebuilt but I still have the following
> problems:
>
> 1. Car will not start without start fluid
The real answer was that the carburetor was not getting any fuel. The problem
was where the fuel line enters the transmission tunnel. I thought that the
fuel line was one piece of tubing from the tank to the fuel pump. That was
incorrect. After the fuel line enters the transmission tunnel, there is a
~6 inch piece of rubber tubing that then connects to the metal tubing that goes
to the fuel pump. This tubing was broken in half. That explains why I could
not get any fuel to the carburetor. I will be replacing this piece this week
and that should fix my problems. Since I had just had the car running several
days before I thought that I was past fuel delivery problems. Not so.
Thanks to all of the people who took the time to reply.
ckotting@iwaynet.net
VanBlanken@aol.com
"Chris Delling" <saschris@flash.net>
richard.arnold@juno.com (Richard D. Arnold)
Peter <nosimport@mailbag.com>
Ulix Goettsch <ulix@u.washington.edu>
--
Bill Gilroy
E-mail: wmgilroy@lucent.com
Telephone: 732-957-4775
Fax: 732-957-4775
77 Midget
================ SUMMARY ================
Below is a summary of what I was sent. Some very good advice here.
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In terms of the "no choke when cold, choke when hot" part of your idea, I
can't see how that's possible. The heat mass (the part that has the
bimetallic spring) only goes on one way, so unless the spring in the heat
mass was mangled, that's not likely to be it. Some "mistakes on assembly"
possibilities exist, however that you should check out: (Note, I'm doing
this from memory, so I could be a bit farmisht.)
1) The fast idle cam and/or the pivot piece that connects the bimetallic
spring on the heat mass with the vacuum pull-off and the choke needle were
assembled incorrectly. Possibilities: (a) fast idle cam installed wrong
way around (so RPMs increase as engine warms), (b) pivot piece misses
connecting with the choke needle or the vacuum pull-off. (c) fast idle cam
is jammed against a protrusion in the choke housing, so it doesn't follow
the choke mechanism. I've done all three of these at one time or another,
and this sounds like the culprit to me.
2) The spring in the vacuum pull-off was installed the wrong way, or not
installed at all. The spring goes UNDER the piston, so that if you remove
the heat mass, it pulls the choke ON. I've done this one too. Since you
assumed that the vacuum pull-off wasn't user-serviceable, this may be
unlikely, but who knows what a PO has done?
3) When you mounted the heat mass, you didn't get the loop in the
bimetallic spring around the tang that actuates the choke. This would
result in either too little choke (if the loop was behind the tang) or too
much (if the loop was in front). This doesn't seem likely to be the
problem, but it's worth checking.
The needle and the vacuum pull-off ARE user-serviceable, and all the
necessary gaskets and o-rings are included in the ZS carb rebuild kit (at
least the one I got...).
When in doubt, check the University Motors Tech pages on the Zenith
Strombergs, and ZS automatic choke.
http://www.universitymotorsltd.com/tech/tech041.htm and http://www.unive
rsitymotorsltd.com/tech/tech042.htm
I would not go the Weber route, unless you were making a number of other
modifications to the engine. A Zenith manual choke conversion can be had
for about $75, or a generic one can be tweaked to fit for about $14. (I
did that on mine for a while, and just converted back over to the automatic
choke. I'm going to use the dash-mounted pullknob to actuate the heater
valve.)
===========================================================================
I would suggest that you check all your vacuum lines, etc, including
those in the vapor recovery system.
===========================================================================
I had a Z-S on my MGB. It was troublesome, and a number of suppliers make
manual choke conversions for this carb.
The fact that your car runs on starter fluid, but stalls as soon as it's
used up suggests that it isn't getting fuel. I would suspect a blocked
needle valve, or misadjusted float, which results in no gas being delivered
to the carb.
===========================================================================
If you don't have a good shop manual on the carb, you should get one. If you
have one, read it carefully and study the pictures. Getting the choke
together and adjusted is really not that hard. It sounds more like you are
not getting enough fuel from the fuel pump. All the choking in the world wont
help with no fuel delivery.
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