23-08-2022, 09:52 PM
I had a recurring fault with very similar symptoms. After multiple attempts to fix, finally with the help of David O, we appear to have sorted it.
The cause was a stripped thread in the distributor base for the screw that holds down the contact breaker base. It was the screw that goes in the slotted hole in the contact base. This screw is required to conduct electricity as well as locate the breaker. Because of the stripped thread, there was poor electrical contact with the threaded metal insert in the distributor base. One symptom of this was heating of the screw head a few minutes after switching on the ignition. It got so hot that it burnt my finger tip.
The poor connection was also confirmed by measuring a significant voltage drop.
Holding the child lead close to the cylinder head while flicking the contacts resulted in a weak spark provided that the lead was close to the head. When retracting the lead, the spark did not jump as big a gap as would be expected.
It's a long shot, but this possible cause may be worth checking.
Regards
Graham Barker
The cause was a stripped thread in the distributor base for the screw that holds down the contact breaker base. It was the screw that goes in the slotted hole in the contact base. This screw is required to conduct electricity as well as locate the breaker. Because of the stripped thread, there was poor electrical contact with the threaded metal insert in the distributor base. One symptom of this was heating of the screw head a few minutes after switching on the ignition. It got so hot that it burnt my finger tip.
The poor connection was also confirmed by measuring a significant voltage drop.
Holding the child lead close to the cylinder head while flicking the contacts resulted in a weak spark provided that the lead was close to the head. When retracting the lead, the spark did not jump as big a gap as would be expected.
It's a long shot, but this possible cause may be worth checking.
Regards
Graham Barker