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Re: high speed miss

To: "Lonn and Rhonda" <hoops@owt.com>, "MG listerati" <mgs@autox.team.net>
Subject: Re: high speed miss
From: <paul.hunt1@virgin.net>
Date: Fri, 8 Sep 2000 19:15:44 +0100
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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