Help needed diagnosing ignition problem Options

[ewok of death]

I have a '75 914 1.7L that I've had for almost a year now. I got it mostly as a 'project' car but I have practically no mechanical experience, and have just been essentially learning as I go. I very rarely drive it, but last week, I was driving it home it suddenly cut out. After stopping, the engine would turn over, but would not start. Upon later inspection with the tow truck driver by holding the HT cable over the engine cover, I determined there was no spark.

So after scratching my head and poking around inside the engine bay a few times, I have come to the following conclusions:

- The ignition coil is a Accel (Super Coil I believe). The resistance across the LT terminals is 3ohms, and the resistance from the battery terminal to the HT terminal is 13k ohms or so (though I may not have gotten an accurate reading and will recheck this in a bit).

- There is a Pertronix Ignitor system in the distributor cap. These I hear are pretty reliable, but the way it was wired was pretty funky. The lead from the battery was connected to the - end of the coil, as was the black wire from the pertronix unit, and a mysterious blue wire that I assume is the tach? The red wire from the pertronix unit was connected to the + terminal on the coil, as well as two black leads (what are these?).

I switched the wiring around so the battery lead, the red ignitor wire, and the supposed tach wire connect to the + terminal, and the black wire from the ignitor and the other two black wires are connected to the - terminal. I read somewhere that the pertronix would work if its polarity was reversed, but would eventually burn out so this seemed like a possibility. Anyway, car still would not start. I tried disconnecting the mysterious wires as well, with the same results.

Then, just now, I went out to measure the voltage at the input of the coil. It was 8.5V or so, which seems about right. I was about to measure the voltage at the - end of the coil, but smelled smoke and noticed that it was coming from beneath the distributor cap, and lo and behold, the pertronix is burnt. Now I am wondering, was the pertronix really burnt out, or did I just destroy it by messing around with it...?

My next step is going to be to test the coil itself by momentarily grounding and ungrounding it directly, but I need to get some leads first.

Just wondering if anyone has any advice, or if they have had similar issues...

Also, if I want to pull out the distributor and install a new pertronix, how can I remove it? Or should I try to replace it with the distributor in place? I assume if I remove it I'll have to redo the timing, or is there a way to avoid that?

[Nolongermusclecars]

I have a '75 914 1.7L that I've had for almost a year now. I got it mostly as a 'project' car but I have practically no mechanical experience, and have just been essentially learning as I go. I very rarely drive it, but last week, I was driving it home it suddenly cut out. After stopping, the engine would turn over, but would not start. Upon later inspection with the tow truck driver by holding the HT cable over the engine cover, I determined there was no spark.

So after scratching my head and poking around inside the engine bay a few times, I have come to the following conclusions:

- The ignition coil is a Accel (Super Coil I believe). The resistance across the LT terminals is 3ohms, and the resistance from the battery terminal to the HT terminal is 13k ohms or so (though I may not have gotten an accurate reading and will recheck this in a bit).

- There is a Pertronix Ignitor system in the distributor cap. These I hear are pretty reliable, but the way it was wired was pretty funky. The lead from the battery was connected to the - end of the coil, as was the black wire from the pertronix unit, and a mysterious blue wire that I assume is the tach? The red wire from the pertronix unit was connected to the + terminal on the coil, as well as two black leads (what are these?).

I switched the wiring around so the battery lead, the red ignitor wire, and the supposed tach wire connect to the + terminal, and the black wire from the ignitor and the other two black wires are connected to the - terminal. I read somewhere that the pertronix would work if its polarity was reversed, but would eventually burn out so this seemed like a possibility. Anyway, car still would not start. I tried disconnecting the mysterious wires as well, with the same results.

Then, just now, I went out to measure the voltage at the input of the coil. It was 8.5V or so, which seems about right. I was about to measure the voltage at the - end of the coil, but smelled smoke and noticed that it was coming from beneath the distributor cap, and lo and behold, the pertronix is burnt. Now I am wondering, was the pertronix really burnt out, or did I just destroy it by messing around with it...?

My next step is going to be to test the coil itself by momentarily grounding and ungrounding it directly, but I need to get some leads first.

Just wondering if anyone has any advice, or if they have had similar issues...

Also, if I want to pull out the distributor and install a new pertronix, how can I remove it? Or should I try to replace it with the distributor in place? I assume if I remove it I'll have to redo the timing, or is there a way to avoid that?

HOW WAS IT WIRED BEFORE?????

I have ran tons of pertronix set ups in a bunch of dif vehicles... I love them. but that doesn't mean something couldn't happen to it. I would throw a set of points in to do all your testing and see if you get spark.... no sense burning another pertronix if something is shorted somewhere else... i wouldn't even go nuts on adjusting just eyeball and check for spark..(wouldn't even run it) then buy the pertronix and reinstall.... check coil for small cracks that may open up when warm.... seen that on tons of things.... return to what was working as far as wiring as well.... sounds like you have a intermittent short somewhere that burnt that thing up... or your wire switching got you somehow... points are cheap to burn out compared to pertronix... i agree with eric the ign key on is no good for anything..... the full 12+ volts (usually two ignition circuits one for run and one for start) it gives at early ignition could overheat and burn anything out pretty quick.... our weld those old points right together that everybody seams to like so much... i say forget points and keep the car running in the 21st century... if points were so great and reliable you would find them under the dist caps of hondas..... Pertronix is the same tech used in any current dist style electroninc ignition... ask a couple old timers how fun it is to set dwell and gap on a old duel point euro dist.... if they say it's fine their lying.....

Good luck!!!!

[ewok of death]

HOW WAS IT WIRED BEFORE?????

The previous wiring:
+ coil terminal: RED wire from pertronix, and 2 black mystery leads
- coil terminal: wire from battery, BLACK wire from pertronix, and one blue/black mystery lead.

So if I buy another pertronix, and wire it according to the 'official instructions' it will be wired exactly the way it is now, which is the same as above, with the battery wire and mystery leads switched to the opposite terminals (probably should have just left those unplugged). This is however, the configuration that let the magic smoke out of the current pertronix, so I'd rather not do that. I need to figure out what all of these wires are for sure before attaching a new pertronix.

I think I'll go with points as some of you have suggested, at least for now. But first I'd like to test the coil independently so I can rule that out.

I should mention that the wire that I believed to be the battery wire once gave me a reading of 0.6 volts, and 9-12 other times. This could have been my multimeter acting funny, but now I am wondering if this is not actually the battery wire, and maybe there is just a capacitor upstream that is holding charge. I'll take another reading on all of the wires later (after unplugging them from the coil of course, don't want to fry anything else).

[Nolongermusclecars]

HOW WAS IT WIRED BEFORE?????

The previous wiring:
+ coil terminal: RED wire from pertronix, and 2 black mystery leads
- coil terminal: wire from battery, BLACK wire from pertronix, and one blue/black mystery lead.

So if I buy another pertronix, and wire it according to the 'official instructions' it will be wired exactly the way it is now, which is the same as above, with the battery wire and mystery leads switched to the opposite terminals (probably should have just left those unplugged). This is however, the configuration that let the magic smoke out of the current pertronix, so I'd rather not do that. I need to figure out what all of these wires are for sure before attaching a new pertronix.

I think I'll go with points as some of you have suggested, at least for now. But first I'd like to test the coil independently so I can rule that out.

I should mention that the wire that I believed to be the battery wire once gave me a reading of 0.6 volts, and 9-12 other times. This could have been my multimeter acting funny, but now I am wondering if this is not actually the battery wire, and maybe there is just a capacitor upstream that is holding charge. I'll take another reading on all of the wires later (after unplugging them from the coil of course, don't want to fry anything else).

When do you get voltage changes??? it needs to coincide with something ie turning ignition switch to start, having at run location???? or you found your problem: a broken wire or shorted wire... there should be no wires that go to coil with power all the time without key in a run position(as far as i know) chase that wire down through harness and find out if it's got physical issues... you have a point about the capacitor but i don't think you would have one there anywhere if switched to pertronix already??? start back at zero and work forward.... i think your "mystery leads" are your run and start 12v+-... red is power to pertronix... leads are power to coil... 1 maybe a tach....