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MG MGB Technical - 1972 B Won't start

Hi all
Happy new year. I have a 1972 MGB GT that I unfortunately have to keep outside, albeit with a good quality cover. I tried to start it after a spell of cold weather, but to no available. Does anyone have a suggestion that might kick it into life before the battery cries enough :(

Thx a lot.

I should tell you to get all of the damp out of the ignition etc etc but I always reach for a can of Easystart. Spray it into the air filters. It always gets mine running again quickly after a winter lay up.
Steve Postins

Depends what you mean by "won't start". Completely dead i.e. no ignition warning light? Warning light but engine not cranking? Or cranking but not firing?

Damp is usually a problem when you get a sudden warm wet spell after a cold spell, and the moisture in the air condenses on the cold engine as droplets. If it's as cold in Belfast as it is here at the moment it certainly won't be damp, but the cold does affect battery performance and how easy it is to turn the engine over, and both of these will result in lower ignition voltage than normal. There can be any number of things to cause reduced cranking and ignition performance, none of which are noticeable in warmer weather, but they make cars more likely to fail as the environmental conditions get worse, and as we aren't used to weather like this these days (weather men are talking about 'extreme' old at a mere minus eight, but 20 years ago Shropshire was getting minus 20 and lower). I have to say that with the battery, electrics, ignition and general state of tune in decent nick you shouldn't be having a problem even at the moment, my V8 lived outside for a number of years and never failed to start even when it was covered in snow or the brakes were frozen on, it and my roadster always start even being left a couple of months or more. Not much fun at the moment, especially if the main objective is to get the car started, but you need to check the battery, charging, cranking circuit for volt-drop, points and plugs condition and adjustment, timing, and carb set-up as soon as you can.

BTW, I've heard of card getting 'addicted' to cold-start sprays. Might sound ridiculous but if the cause *is* poor electrics or poor state of tune then it is only going to get worse, hence will need more and in progressively less harsh conditions, i.e. akin to addiction.
Paul Hunt

THx Paul,
it's freezing cold here in Belfast at the minute. The car turns over ok but does not fire.


Can you hear the fuel pump tick?
Do you have fuel?

Since the float chambers are rarely if ever emptied (unless the car is laid up for many months) there should be enough to start it even if the pump isn't working. Indeed it is one of the reasons behind putting an imobiliser switch in the fuel pump - it allows a tea-leaf to start the car and get it out into traffic, then it conks out. It would take a brazen thief to then fiddle with it instead of running off. Also once the ignition has been turned on and the pump is working, turning the ignition on subsequently without the engine having been run will only result in possibly one click of the pump, and not even that if you switch off and back on again within about a minute.

A timing light on the coil lead and plug leads is the first step, and watch for flashing as you crank. If no flashing on the coil lead you need to do voltage checks on the coil and points. If the coil lead is flashing regularly but the plug leads aren't then the rotor or cap is breaking down. While on plugs 1 or 4 point it at the crank pulley and check the timing is about 8 degrees BTDC. If that's OK take out plugs 1 and 4 and sniff them. No fuel smell means no fuel, soaking wet means they are flooded, they should smell strongly but not be wet. If you do flood it you should almost certainly be able to smell unburnt fuel around the car. To un-flood it push the choke in, floor the throttle, and crank. Be ready to release the throttle and half pull the choke if it should fire. Sometimes pulling the lead out of the coil by about 1/4" can encourage a reluctant starter as the coil voltage has to rise higher before it will jump the additional gap.
Paul Hunt

This thread was discussed between 05/01/2009 and 07/01/2009

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