MG TC starting problem

[briandshepherd]

Bit confused here....
Have had 1948 TC5124 since September last year and although it is in very good original condition, doesn't appear to have done more than 70K miles in its life, and has run and driven perfectly since then.
Having been garaged for about 3 weeks it now doesn't want to start having being running perfectly before and nothing changed since.
Have power to the coil and points, but am not getting a spark at the plugs, yet nothing has changed since last used 3 weeks ago.
Am suspecting distributer capacitor or coil and wondered if these are things that fail just like that as both appear to be original ?

Any advice or experiences with this old engine would be appreciated.

Brian

[Clifford Jay Lockrow]

Rotors, especially later one, are known to fail. Try a new one and look in your magazines etc. for one of the "red" bakalite rotors. Better quality. Also try a new coil I have had these go bad a few times over the last 54 years. Sometimes the car will start cold but go bad when warm. This is a sign of a bad coil.

[Duncan M]

Check, clean, dry ignition points.

[Steve Simmons]

Condensers don't usually fail suddenly unless you're running electronic ignition, which usually do fail suddenly. Check for moisture inside the distributor, then all I could suggest is replacing things one at a time. I agree with the above advise to use the new red rotors. They are far higher quality than most others on the market. Obviously check the points as well in case moisture got in there and corroded things.

[Richard Michell]

What do you mean by "not getting a spark at the plugs"? Is this with a plug removed and laying on a metal part of the engine?

To track down the problem a little more, suggest take off distributor cap and remove high tension (centre) lead from it. Rotate engine by hand until points are closed. Turn on the ignition, hold exposed end of the HT lead near a metal, unpainted part of the engine and flick open the points a couple of times. Do you get a fat blue spark across the (approx 1/4 inch) gap between the HT lead and the engine? Don't do this too many times as it could overheat the coil if a spark is jumping.

Successful spark indicates that coil, condenser, LT circuit and points are OK.

[briandshepherd]

Thanks, Clifford, Duncan, Steve and Richard.

Really appreciate your help here and I now have some new ignition components as well if required to try out every thing and diagnose the fault but won't be able to get to it for a couple of days.

As you all say it can't be rocket science, it's just that I wondered if there was a particular common fault with this engine.
It has to be either coil, leads, rotor arm or points and I will get it sorted and let you know thanks.

Brian

[briandshepherd]

Sorted …

After checking all sorts of HT and LT connections and getting frankly, inconsistent results I have found and sorted the problem.

The capacitor ….. which is the original soldered type to give the earth to the baseplate but, it has a little nut on the end which connects a metal strip to the distributor LT terminal completing the circuit, and that was loose giving an inconsistent connection. …… once tightened it started instantly and runs fine now.

Simple, but not immediately obvious and very frustrating as I was looking for a bigger problem than it actually was.

Brian

[Steve Simmons]

Isn't it always something simple (but not obvious)? Glad you got it sorted!