Welcome to our resource for MG Car Information.



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 MGA - Coil and point trouble

Awhile back I had my coil fail so to get it home I just thru a coil I had laying around,a MSD blaster 2. It says to use a resistor but I just didn't have time to fool around on the side of the road. I got home ok but now as I go to put the car away for the winter I'm having trouble. I am going to get the correct coil and for piece of mind have my distributor rebuilt. My question is after about 2 min running at the most the points get so hot that the plastic rubbing block softens and closes the gap and quits. Is this because of no resistor? I thought that no resistor would cause the points to maybe arc more or overheat the coil. Back in the "good" old days the rub block was phenolic and could take some heat compaired to plastic
gary starr

Gary, measure the coil primary resistance. If it is about 3.5 ohms it does not need a resistor. If it is about half that, it does.
Art Pearse

Art it is measuring around 1.5 and even MSD says you need a resistor. I am just surprised that the points themself overheat,I thought the coil would overheat. I only have to move it up hill about 100 ft total to get it put away for the winter and was going to address my problems then but as it now sits,in under 2 minutes the rubbing block melts enough to close the point gap stopping it.I have just ordered a new coil and a set of points and will go from there
gary starr

Gary, maybe your points are bad and have about 1.5 ohms res, so total of 3 ohms - OK for the coil, but generating 4 amps x 1.5 ohms i^2r = 24 watts - enough to do what you observed!
Art Pearse

They were brand new,I got at most 8 miles on them. It has to be the coil with no resistor overheating them. Should know after I get the new points and coil. Once I get it into it's sleeping spot I'm sending the distributor to Advance Distributors to let them work their magic!
gary starr

This thread was discussed between 15/10/2013 and 17/10/2013

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.