I have a '77 MGB that has some health problems. They appear to be
related to the carbs. BTW this car has a 18GB-U-H engine (crica 1965),
1972 HIF4s on it, and no special cam or crank.
As some of may know that I have had numerous problems with this car
since I have been here in Phoenix. Well last night in the process of
changing the points, condenser, plugs, wires, rotor-cap, and rotor.
And finally I got around to adjusting the carbs. Her comes the
interesting part.
I take off the filters and check the jet adjustment, this "APPEARS" to be
ok. "APPEARS" is the key word here. I do the lift the dashpot thing, and
the rear one appears to work ok, so I give it the acid test by lifting
the dashpot all the way up. The car does not die, it sputters a little
and settles back into a reasonable idle. This strikes me as a little
strange, as in out of the norm. So I do the same test on the front carb,
it has some problems it almost dies when lifting for the idle check, and
does die if the dashpost is lifted all the way up. Which is what I would
expect.
So I start checking everything, like loose vacum hoses, etc... What I
found were no lose vacum hoses, but the over flow tube on the front carb
is sucking air like crazy. If I try to put my finger over it to plug it,
the car dies. So I try this trick on the rear carb, it is not sucking
air and does not die when plugged.
The car appears to run fine. No misses, the noticeable thing is that at
idle the tempature is where one would expect to find it. While driving
in town or on the freeway it will overheat. At first I thought that I
had a bad thermostat. I changed the thermostat no help. But with the new
revelation about the carbs, I think I probably have a car that is
running way too lean while driving, but ok at idle. Oh, BTW, while
driving down the hiway it will occasionally surge from time to time.
This is not noticable in town at surface road pace(stop and go at lights).
So my question is does any of this make sense, if so then what does the
symptoms sound like. The carbs were just rebuilt before coming here to
Phoenix from Austin. My best guess is that the seals in the carb(s) are
shot, or possible I have a lack of vacum because of some port being
plugged.
Any thoughts, suggestions, advice, criticisms, etc is greatly
appreaciated. As I would not like to take my car down and let a mechanic
work on it. I would much rather "swork" on it myself.
Bruce "Very puzzled and confused, maybe even lost without hope" Carter
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