Basic auto ignition electric Q

Old points system was in the distributor prior to conversion. Yes car was running recently. No issues with points/capacitor ignition performance (car was driveable, normal). It's been a few months since then (it's a slow project...).

Coil was replaced as part of the conversion. I've examined both coils and compared resistance measurements; not much difference.

Reply to
Paul Conners
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snipped-for-privacy@panix.com (Scott Dorsey) wrote in news:hbkeu6$jif$1 @panix2.panix.com:

That may not have been true for all makes.

It's been a few years, but I'm pretty sure the condenser was a separate charge for me when I bought OEM points for my '74 Mazda.

Reply to
Tegger

Tegger wrote in news:Xns9CAAC5321C512tegger@208.90.168.18:

unless you bought a tune up set they were always seperate. KB

Reply to
Kevin

That is the way I remember it too..Havent been around a car with points and condensor for a long time.

It was unheard of to replace points without replacing the condensor, although most of the old condensors were probably good.

Reply to
hls

to answer the OP.. most coils do not have an actual ground connection..

the current in the secondary flows to ground through the primary circuit. The low side of the secondary is connected to the primary.

also the condenser in the old point systems do not serve the same purpose and are not connected the same as in a modern car.

In the old system the cap was across the points and protected the points when they opened by absorbing the current flow... and the cap needed to be rated for a high voltage like 400 V

In todays solid state system, the cap is usually just on the primary

+12 supply to ground to keep the ignition pulses flowing in a smaller area loop to reduce EMI and radio interference. The car will usually run fine without this cap but the radio will static. This cap just needs to withstand the +12volts (and any surges that may be on the +12volts which can be considerable like 80 Volts.)

Mark

Reply to
Mark

also the condenser in the old point systems do not serve the same purpose and are not connected the same as in a modern car.

************ Sort of... The old cars may have also had noise suppression condensors.

The ignition condensor WAS connected across the points, but if you look at the schematic you will see that this was also between the coil primary and ground. The condensor served, as you said, to help protect the points, but it was more than that. The tuned circuit also had a purpose.

New cars ignition systems may be totally different from those old Kettering systems.

We took this on in a thread some time ago.

I am wondering if his magnetic ignition system is either faulty or hooked up incorrectly.

Reply to
hls

OP, here.

That's what I'm trying to determine. I'm 99 percent sure polarity was never wrong (instructions say that will kill the module). Hookup is pretty simple: red wire to coil primary (+) which is also battery (+). This car has no ballast resistor nor primary resistance wire so coil primary is at ~ +12v. Black wire to coil primary (-). Apparently the module also uses the distributor body as its ground connection. A clamp bracket (to keep the distributor from turning) grounds the distributor sufficiently.

Product support folks say no capacitor is needed. Both coils (original, and new "hot" output coil) result in no spark.

Next time I'm at the car I'll do resistance tests on the module per the support folks' specifications. This will determine the module's health.

Reply to
Paul Conners

An ignition capacitor is normally only needed when there are mechanical points involved. These old systems often used full battery voltage on the coil for starting only, and switched in a ballast resistor after the key was moved from START to RUN. 12-13V put too much current through an unballasted coil on a full time basis, and would overheat points (and coil) if allowed to run that way. (Yes, I know there are other variations)

I smell a bad module or sensor, maybe. Occasionally people hooked up their wiring to the Kettering system incorrectly, and ended up with reversed polarity. Sometimes the cars would start and run reasonably well.

Point is, if you get a replacement module, be absolutely sure what your polarities are -everywhere - before you power up the module.

Im sure you know that, but ........

Reply to
hls

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