Advance problem, is my guess. Is the vacuum advance diaphragm still
intact? Are the distributor mechanical advance weights free, or stuck,
and are the springs intact and correct? What kind of shape is the
distributor in overall?
David Littlefield had this to say:
>OK, folks, here's a puzzler that's been driving me crazy. Hopefully
>someone out there can give me some things to check.
>I've installed a 1967 MGB motor in my MGA MkII. I just can't get it to
>It will idle great and will accelerate fine up to about 3000 rpm in first
>gear. It then starts to bog and miss. It will do this a little later on
>the rpm curve in each of the gears. By the time I get to fourth gear, it
>bogs and misses around 4500 rpm.
>So far I've been through the entire fuel system:
>New pump (for other reasons).
>Blown through all the fuel lines and checked the tank for debris.
>Changed fuel filter.
>New points and condensor, swapped out coils. New spark plug wires and
>cap, swapped these out with old ones just to check 'em.
>I've adjusted the carbs using a Uni-Syn and a Colourtune.
>Any suggestions or (wishfully) magic bullets?
>'62 MGA MkII
>'74 MG Midget vintage racer
>'88 Jaguar XJ-S
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.