Moss Motors, Ltd

Problem with car at slow speed.if pulling away from a standstill it feels like engine has a slight misfire,and if stopping at traffic lights it will actually cut out, this is a real pain if there is much traffic about.But when on the move  or accelerating,it pulls well, feels fine and sounds great.I have replaced plugs,leads,dist.cap,rotor arm.mixture looks ok.by colour of plugs.oil pressure/water temperature are fine and engine does not burn any oil.i was thinking of maybe it could be vacuum advance or something like that.any ideas.

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phil wilkins

When at rest, is it possible that you heater valve is leaking onto the distributor?  When at speed any droplets could be blown past the distributor.

Hi.thanks for reply,i fitted a new heater valve earlier this year,but have not checked to see if there are any leaks.Will check this out.

thanks

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phil wilkins

mine was doing this for months, i tracked it to water and rust in the fuel tank

 

i bought a stock of cheap £1 fuel filters and changed them weekly until the gunk had been displaced from the tank

Phil, It sounds like its time to touch up the points and maybe change the capacitor, particularly if its the original, by now a bit wobbly, distributor!!

If you do have a bit of water in the tank, alcohol based gas will pick it up more smartly than the other stuff. Hope you get it fixed.

steve

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To a man equipped with only a hammer, most problems look like nails

If none of the above advice has helped (all good ideas) check for a minor vacuum leak at the carburetter to manifold gasket or at the manifold to head juncture. A small aperture leak would make a large percentage of difference at idle, but because of greater volume at speed, would be "overcome" by the system and not make a great deal of difference. I've seen this often before.

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Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

Hello,thanks for reply,i have now cured the slow speed problems.the man at the restoration garage where i have some work done occasionally on my mg,says it was a problem with the gasket between one of the carbs and the inlet manifold.Anyway,one new gasket later and reliability has returned.

I do have a couple more questions if you could help.

When you change the engine oil,how long or how many miles do you think it would normally be,before the oil is a black colour again ?.

At what stage would you consider fitting a reconditioned gearbox ?  gears change ok.with no problems,but there seems to be quite a lot of noises coming from the box.they diminish a bit when the engine is hot,but compared to my ford ka it sounds a bit agricultural.Also,if you rest your hand on the gear lever,it seems to make noises worse.the chap at the garage says he has changed the gearbox oil for me.i have not driven another mgb so maybe some gear noise is normal,i don.t know.

many thanks      phil.

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phil wilkins