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MG MGB Technical - no power when hot

Hi to you all. I have a problem with my GT. It runs fine for 10/15 miles temp gauge up to normal and then the engine has no power. It will tick over OK and will rev if the accelerator is gently depressed but under load will loose all power and back fire. Petrol to carbs look OK plugs new points OK dashpots full. When the engine cools down it will run for ok for some time. Got any ideas?
ROY

Has this only happened since having worked on the car...i.e. fitting the 'new plugs'?

Dave
D O'Neill

No fitted last year and did the IOW trip OK
Roy

Roy,

Have you checked that the choke is working properly, if its not returning it will give an over rich mixtuer once the car has warmed up and cause the problems you are experiencing. Check the plugs to see if they are black which would be an indication.
Kevin.
Kevin Jackson

I changed the O rings last year on the choke units HS4s as this was over choking. When I have the problem pulling the choke out makes it worse.

Thanks for the replies
Roy

It would be worth pulling the plugs when you have the problem as a quick way to check if it is rich.
Steve Postins

A bad ignition coil may cause trouble only when hot, the condenser could also be the problem.
John H

New coil but have not changed the coil condenser will get one at the weekend

Thanks
Roy

Roy

I put my money on the condensor. Even some new ones are prone to failure. Might be an HT lead aswell but try condenso first, cheaper.
Richard Evans

I had similar overheating on a V8 - it turned out to be the inline resistor to the coil that was getting hot and changing it's resistance.
Ted

This thread was discussed between 12/03/2007 and 18/03/2007

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