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MGB Need help diagnosing MGB engine issues

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OK, I think my coils are internally ballasted I get about 4 ohms resistance on each at the two terminals, as I was thinking about this maybe Tims problem internaly ballasted coil with external ballast added, or non ballasted coil with no external ballast? Just some maybes to think about. Also have you pulled the plugs? do they look black? brownish gray? wet? dry?
 
Unless the system has been changed for some reason the coil on a 72 will be internally resisted.

In testing a coil not having been used for a few minutes, measured across the primary terminals, an externally resisted coil will fall between 0.5 and 2.0 Ohms while an internally resisted coil will fall around 3.2 to 3.5 Ohms. These figures will vary according to the make and age of the coil and the meter being used.

Remember that a stalling/stumbling symptom can be caused by a coil "partly" failing. With the engine being started and running for a brief time the coil functions correctly but as the coil naturally heats during use the primary windings may open. As that circuit is rendered incomplete the coil either cuts clean and the engine stops or it may go through a short period of off/on during which the engine either stumbles of gradually looses power until it stops running.

Hope this helps.

Jack
 
And now for the "AH-HA!" moment you've all been waiting for (drum roll please)...

It was a loose base plate. I spotted it right away as I was getting ready to disconnect the condensor (almost 1/8th of an inch of wiggle - enough to open the gap between the contact points considerably. I went ahead and put in the new condensor, rotor and points. Once things were reconnected, there was absolutely no movement in the base plate. I regapped the points and reset the static timing, and started it up with no problem. Took it out for about half an hour, got it good and warm, and had no problems at all, other than a possible pinging on aggresive acceleration in fourth hear from my poor static timing. I will time it with a strobe light soon to fine tune things.

Many thanks to all, and Greg, I've still got your coils at work and will try to get them returned to you soon.

Regards,

Tim C.
 
Bruce Bowker said:
Long shot but I went through the same thing. Went over every inch of the ignition which was obviously the problem only to find out it was the fuel draw tube in the tank plugging up (slowly) as the car ran.
Click to expand...

We had a similar problem on the wifes B. Found out that the suction line from the fuel pump to the tank had a crack in it. Couldn't see it behind the braided line. The car would run fine for about 2 miles and then die. Setting for a minute, it would run for another 2 miles. All this because the nitwit that restored the car forgot to replace it. Guess who that was? :rolleyes: PJ
 
Tim, no rush on the coils, sitting in a box for many years, when you get a chance, glad it turned out to be simple and the car is running well now.
 
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