Sorry for the cross-list posts, but since this carb is common to both
platforms, I figure there must be an expert out there willing to tell me
what is going on.
I have a '77 MGB that is my daily driver. It is equipped with said Weber
carb. This car starts up perfectly, idles perfectly, and runs at speed
perfectly. However it seems to "load up" at between 100-2500 rpm. What I
mean by that is that if I drive normally and come to a stop light, when I
take off, it seems to miss like fouled plugs until 2500 rpm, then it clears
up and runs like a scared rabbit. The engine, an 1800, has a standard head,
desmogged, slightly bored out, new cam, pretty much everything new on the
engine in the last 10K miles.
To add to the mystery (to me) is the fact if I keep my foot out of it and
accelerate very slowly, this miss is gone or almost gone. If I accelerate
quickly, it is bad until 2500 RPM. Plug color is good, plugs are fairly
new, tail pipe inside color shows it may be slightly rich. Good gas
mileage.
I thought it may be fuel pressure. I have a Holley regulator and gauge set
at 1-1/2 to 2 PSI.
I'll be the first to admit I know little about this carb or webers in
general. It was on the car when I bought it. I am very seriously thinking
getting a set of SU's. At least I know those.
Another part of the puzzle that may help you experts. After the car is hot,
I have to start it holding the accelerator down, but again, it usually
starts on the second turn over.
Any ideas? This thing does not appear to have mixture screws anywhere that
I can find. How are you supposed to adjust it?
Thanks,
Bill Miller
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