MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - CAr just stops (electrical?)

I have a 78 mostly stock with Weber carb. It recently started dieing after 30 minutes or so of driving. after setting 2 to 10 minutes it will restart and run 10 to 20 minutes longer. I think the problem is a loss of power to ingition system. Any ideas?
Jimmy Chew

Coil
Art Pearse

Is your car by any chance still fitted with the original Lucas 45DE Opus electronic ignition? I had exactly these symptoms on my '79 many years ago and effected a cure by changing the distributor to a more reliable type. The problem was the ignition module. The 1980 model got a (disguised)GM module.

Kevin
K J P Kelleher

Before just plumping for the coil and finding it is something else, what does the tach do when this happens?

If it drops to zero suddenly, even when the forward motion of the car is still spinning the engine, it is an ignition LT problem i.e. ignition supply, coil, points/electronic trigger, or the connections between them. If the ignition warning light is glowing while the engine is spinning then it's probably loss of voltage from the ignition switch.

If the tach still registers and only slowly drops as the car slows then it is ignition HT or fuel, or possibly condenser if you have points.

If fuel then the pump will chatter like billy-oh the next time the car starts - assuming you have an original SU type. If not then HT or condenser.
Paul Hunt

Jimmy, my car did that, too. It was a ground connector that wasn't making contact.
On the inside of the bonnet, passenger side, there are wires from the fuse box, coil, etc., that are screwed to the wheelwell. Disconnect them, and sand down the connectors to remove corrosion.
I do this annually. It solves my problem.
To lengthen the time it takes to corrode you can use a coating on the connectors. They sell it in auto parts stores.
Randy
1977 MGB
Nancy Olson

Great advice Randy, I just got through sitting on the side of the road for 2 hours for that very reason. Local mechanic did a hot wire for me but it still drove me nuts. I took my fuse box clean off and wirebrushed all the terminals. But....any ideas on how to clean the female spade clips?
Keith Yarbrough(TD 1275)

Hi Keith,

Get some 400 wet and dry emery paper, cut a 1/4" or slightly less, wide strip, fold it over itself, so that you now have "double sided" emery, push in and out of the connector a few times, till there are metallic signs on the emery. Finally tighten the connector slightly with pliers.

Herb
Herb Adler

This thread was discussed between 15/06/2013 and 16/06/2013

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now