My Carbalancer finally arrived, so I tried tuning the HIF-4 carbs that I put
on my 1980 MGB today. The idle had been running at about 1200-1800 RPM,
which was much higher than I had wanted. However, after balancing the
carbs, the lowest I was able to get was about 1200. I was only adjusting
the idle screws; the fast idle screws were not touching anything, and I
didn't play with the mixture screws, having set them when I last tried to
tune the carbs with the Colortune. The front carb seemed to be running
richer than the rear carb, so the idle screw on the rear was down about 1/4"
while the front screw was not protruding at all.
I haven't taken these carbs apart, so I don't know which needle they have.
When I bought them, the PO said that they had been professionally rebuilt
and had passed the CA emissions tests easily, so my assumption was that they
were set up right.
I had set the timing before (about 14 BTDC), although I haven't checked the
valve clearance in a while. I believe that both of these are supposed to be
done before tuning the carbs, so I know I haven't been thorough. There also
was an air leak around the intake manifold which I think I fixed, but it
could still be leaking a little.
The car seems to run OK other than the high idle. Any suggestions on what I
can do to set the carbs up correctly? Thanks.
--Steve (1980 MGB)
|