Mike:
Never satisfied, are you? You get it running great after
replacing the plug wires, and now you have decided to make more
improvements. Tsk, tsk. I hope you have a good therapist to help you
through your obsessive behavior.
I am suspicious of your upgrade to a Grose needle valve (you
*DID* mean needle valve, didn't you? Or did you replace the jet and not
the needle valve? Or both?)
True confession: I was considering a 240Z as my next project
car, but gave up on that idea. Not quirky enough for me. Ahem. Anyway, I
was on the Nissan Z mailing list for quite a while. The early Zs use
Hitachi built SU carbs under license. The Grose needle valves were
universally viewed with suspicion by the experienced list members and
reports were very mixed by those brave souls who tried them anyway.
So, based on nothing more than some email chatter (about
Japanese carbs, no less. Well, they were designed by the Brits at least)
I am going to cast blame on your Grose needle valves (assuming you meant
needle valve, and not jet.) Go back to your Zenith needle valve and see
what happens.
If you did in fact mean Grose *jet*, then is it possible you
have the wrong size? The CD175 Zenith carbs use a 0.100 size jet, but
there are some models that use a 0.090 jet. So if you got a 0.090 jet
instead, with a standard B1AF needle then the jet would be blocked at
idle and no fuel will come out.
That's my worthless opinion.
Keep us posted,
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of DaCRANEz@aol.com
Sent: July 12, 2005 8:58 PM
To: 6pack@autox.team.net
Subject: Triple carb help
I think I have gotten in way over my head. I installed a Goodparts
triple
carb set-up. Bought a used carb and rebuilt it (diaphragm, needle,
gaskets, Grose
jet, shaft seals, etc.) Installed unit and at first all seemed well.Then
It
started a regular miss that I could not tune out. By pulling plug wires
I found
that #3and 4 cylinders were not firing. Checked for spark-plenty of
that.
Seems no fuel is being drawn through jet on middle carb (used rebuilt)
Float bowl
is full. Carb acts like a huge vacuum leak. Putting my hand over it
makes
engine speed up. I have checked for any and all other vacuum leaks,
changed spark
plugs, removed pertronix and installed new points,cap and rotor, reset
timing, checked float level, checked compression-180 psi, checked valve
action-all
bobbing up and as they should. New sealing caps on vacuum ports . Bypass
valves
closed. Only thing not replaced on carb is temp compensator. Engine now
has
gone from steady miss to speed up-slow down mode-running only on 1,2
5,and 6
cylinders. The more I check the worse it gets. Anybody with a triple
set-up have
similar problems? Anybody with a fresh idea. Help!
Mike C '71 TR6
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