1934 Phantom II - can coil and magneto die simultaneously?
Any clever ideas very much appreciated. As you will note from the below, I am not a mechanic, nor an autoelectrician, and rely on the expertise and advice of others. I do my best with learning as I go on.
The weekend of 26 January, I drove the 1934 Phantom II a glorious 96 miles, 65 or so of which was on Sunday on a run with the Jaguar Club.
Apart from a slight misfire, which had been manifesting before, and for which I was intending to have the plugs blasted clean in due course, all was excellent. This included a few stops and switch-offs, including a long stop for breakfast.
On the return journey, she suddenly started feeling as if she had fuel starvation on the highway. Every now and then the power would go and it would feel like fuel delivery was not great, or something similar. The closer I got to home, the worse this started getting. As the fuel gauge was faulty, and I had done 93 miles since last filling her, and she had a bit of an overflow fuel leak when the tank was very full, I thought perhaps she was running out of fuel. So I added 30 litres (not wanting to overfill given overflow issues). The attendant said he could see the fuel level, but I could not. Be that as it may, she then manifested the "fuel starvation" problem heavily on the next start, until she cut out at the lights some 100m down the road from the station. Starter turning nicely, but no firing engine. This happened for about 10 very nervy minutes, with taking and then retrieving emergency triangle from down the road (no companions). Engine started up again (thank goodness), and she drove to the underground parking garage where I keep her weekends, what with intermittent "fuel starvation" all the way there. Arrived there, she suddenly idled quite nicely.
Remember there was a slight misfire. When I was testing the ignition for the misfire the weekend before, it appeared the misfire was in the battery plugs, as she idled very smoothly on magneto but misfired on battery, so driving on M & B saw her misfire a bit.
Anyway, idling in the parking garage after this disquieting return journey, I played with the ignition advance and retard a bit and found the best spot to be about exactly half. This was standard for her performance since I've had her.
I then switched her off after parking. On trying to restart her about 30 minutes later, I could not get her going at all, whether with choke on "running" with throttle use, or "extra oil and rich" or "starting" with or without throttle use.
Previously, I was advised there had been an occasional problem getting her going if the Autovac unit did not fill properly - this would occur if the carburetter float bowl was empty (tested with thin screwdriver), and one then needed to prime the Autovac with fuel through a screwhole that had been drilled for this purpose (before I got the car - let's not go there). I had never myself had this problem the 9 times or so I had driven her - she had started properly every time. Anyway, I checked the float bowl, which was buoyant, suggesting this was not an Autovac filling issue, but filled the Autovac anyway with fuel. No joy.
My mechanic said this sounded like a fuel blockage somewhere. I readily agreed, as this was very similar to the problems I experienced in the E Type until I had the fuel system flushed and the fuel tank properly lined.
When my mechanic attended a few days later, the fuel filter showed clean fuel, the starter still turned nicely, but there was no spark at all. The coil did not heat up at all. But the magneto also produced no spark at all.
Tomorrow, we are going to try a new coil and condenser.
But I am told the magneto system and coil (battery) system are entirely independent, meaning the magneto and coil appear to have failed simultaneously. This sounds very unlikely to me. Is there some electrical point prior to both magneto and coil that could be responsible for lack of spark from both magneto and coil?? I would hate to go to electronic ignition and essentially abandon the magneto if the fault is somewhere earlier in the system.
I would sincerely appreciate advice on this issue before my mechanic attends tomorrow at around 08.00 am GMT. I'll look again late tonight and hope for some insight.
1934 Phantom II Sedanca de Ville
1963 Jaguar E Type 3.8 FHC
1933 SS1 Tourer