Yesterday, my '75 RHD std beetle wouldn't start (It might be easier if you think of it as a '74 since it has a 34PICT-3 carb and the dizzy is the same as a US-spec '74). It cranks but won't start. Not even a hint that any of the cylinders are firing. This is odd since it was running yesterday, though it did seem to be missing a little. At first, I thought I was out of gas (fuel gauge reads near the top of the reserve area), but today I took the air cleaner off and moved the throttle and there was definitely fuel squirting from the accelerator pump tube into the venturis. So, I started to look for an ignition problem. I'm running the stock coil and distributor but have replaced the points w/ the Empi electronic ignition unit (looks just like Comp-U-Fire). All distributor parts are less than a month old (plugs, cap, rotor, wires, electronic point unit). I just set the timing to 7.5BTDC yesterday. Prior to this it was mistakenly set at 5ATDC. Because it's running an electronic ignition, I'm hesitant to leave the ignition on w/o the engine running for any significant time (more than a few seconds). The instructions say leaving the ignition on w/o the engine running could damage the unit.
Here's my troubleshooting so far: I first looked for voltage at the "+" terminal on the coil w/ the ignition on. My digital multimeter reads 11.8v. For comparison, the large terminal on the alternator (with the thick red wire) reads 12.3v. Both seem a bit low to me, but I have been cranking the engine a lot in an attempt to start the car. The car still cranks strong w/o any hint that the battery is getting weak.
To test the coil, I disconnected the electronic ignition from both the coil connections (+/-). With the ignition "on" I connected a length of wire to the "-" side of the coil. This would act as my manually operated points. I pulled the coil wire from the dizzy and held it close to ground (intake manifold heat riser). I then grounded the "-" wire for a second and removed it from ground. This should cause the primary circuit to energize and colapse, sending a nice charge out the HT wire to ground... I didn't see anything (this was done in the evening). I was holding the HT wire about 2mm from the manifold. I saw nothing until I let the HT wire touch the manifold. Then there was a small arc. To try and improve the lenth of the arc I wired the "+" side straight to the alternator post to get the best "quality" voltage I could. No change in the results.
I pulled the coil from the car with it still wired to the alternator connector and used the alternator case as my ground. Again, I could only get a consistent arc when the HT wire was touching the alt housing. I was able to occasionally get an arc to jump the smallest of gaps (0.5mm), but 1/8" or 1/4" was out of the question.
Does this sound like my coil has gone bad? Was the above test acceptable for testing coil output? Could my problem be the battery is too weak at 12.3v? Could the electronic ignition have been too much for my old coil (my meter showed almost 70-deg dwell w/ the electronic unit) and killed it?
One last question, if I pick up a new coil that doesn't measure more than 3ohms across the primary circuit, can I add (or make) an external ballast resistor so it won't burn out my electronic ignition?
AshMan