Ignition System Question - 1974 L48

[Robert S.]

I am troubleshooting my L48 1974. First start after winter storage had the idle speed jumping around, engine quitting suddenly but restarting ok and has now deteriorated where it sometimes will not restart at all or restarts with much difficulty. I think it is ignition related since when it would not restart I tried spraying starter fluid into the carb and it would not pop at all. Hence my question about the ignition system.
When I do a continuity check placing one lead on the coil terminal going to the distributor and the other lead on the advance plate ground wire that is attached to one of the vacuum advance screws I get a complete circuit with the points closed. This is what I expected however when I then pried the points open I still got a complete circuit.
Am I doing an illogical check or does this suggest the Uniset type points are shot? The points have only about 300 miles on them.
P.S. Even more strange is that everything worked fine when I took the car off the road for the winter last Dec.
Any other troubleshooting ideas would also be welcome.

[Jack H.]

Re: Ignition System Question - 1974 L48

Probe directly across the contact points when you make this measurement as the condensor is in-circuit and it can be 'charging' based on the probe current of your multi-meter set to resistance mode. Plus, it IS possible that the condensor in your uni-point is bad...

Another question is why have you decided the problem is electrical/spark related? A common source of such problems (rough running after LONG storage) is often the QJet. If you have a factory original nitrile coated float, long periods of sitting dry (especially with today's alcohol dopped fuel) can result in the nitrile coating cracking/flaking with the float progressively 'water logging' and sinking. This would result in excess fuel and an over-rich mixture that would worsen with time after the carb's fuel bowl was re-filled after dry storage....

[Jim T.]

Re: Ignition System Question - 1974 L48

After winter storage it does run, but hard to start but does run. A cleaning inside the carb may be needed as well as a replacement of the accelerator pump to get a solid injection of fuel for starting and acceleration.