Did you set the points to the recommended figure? have you checked them
with a dwell meter? An excessive gap will cause a high speed/heavy load
misfire.
You can check the condenser by removing the distributor cap and flicking the
points open. By holding the king-lead (suitably insulated from you) by the
block you should be able to draw a spark out to at least 1/4". If it barely
jumps a plug gap, and especially if you get a lot of sparking at the points,
the condensor is not doing its job.
Does pulling the choke out (if manual) cure it? If so it could be fuel
related.
PaulH.
----- Original Message -----
From: Lonn and Rhonda <hoops@owt.com>
To: MG listerati <mgs@autox.team.net>
Sent: Friday, September 08, 2000 4:32 PM
Subject: high speed miss
> Our 70 BGT has suddenly developed a problem. At low speeds, even under
> heavy acceleration, it runs fine. But try to accelerate beyond about 3000
> rpm and it starts missing and tops out at about 4000 rpm under load. I've
> checked the plugs, they look normal, the points had collapsed to about 10
> thou so I opened them back up, and the cap and wires are 3200 miles old.
> Fuel pump runs like crazy if you unhook a line to the carb. This is a
fresh
> rebuild with 3200 miles that has been running perfectly until yesterday.
>
> Not the coil, I replaced it with the good one from my TR6. Condenser
maybe?
>
> I hate to go replacing things at random. Anybody been there, done that?
>
> Thanks,
> Lonn Howard
> Pasco, WA USA
> '67 Land Rover 109
> '70 TR6
> '71 TR6
> '70 MG BGT
> '89 Saab turbo 'vert
> '91 big Chevy truck
>
> "We are just temporary custodians with an obligation of preservation."
>
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