Ignition System Question
 

Here’s a question for all the MOdel A ignition system experts.....

I’ve recently experienced an ignition system failure - no spark - during a tour in the city with lots of stop and go driving and temps in the low 90’s. No engine overheating at all. More recently than that, after installing a new Pertronix Flamethrower epoxy filled coil, and new condenser and cleaning the points (yes, original stock ignition system), which had about 1200 miles on them, I now experience an occasional high-speed miss after the engine has warmed up and run for 10-15 minutes. At 40 mph.

I’ve recently rebuilt the Zenith-2 carb, with Renner’s Corner flow tested jets, and cleaned the fuel filter.

This afternoon, I pulled the Champion 3X plugs (1200 miles on them) and they do not have carbon build-up - very clean looking. However, the gap on a couple of them was almost 0.050” - not sure how that happened. Anyway, I’ve re-gapped them to .035 and am wondering what the effect of too-large a spark gap on the coil would be.

Could this cal the coil to overheat ?? Or does this sounds more like a condenser issue ??

Thanks in advance -
JIm

Re: Ignition System Question
 

"Pertronix Flamethrower epoxy filled coil"

I had one of these on two different cars. Both exhibited the same failure mode. When I would stop for gas on a hot day the temp under the hood would elevate and the car was hard to start and would run poorly until they cooled down. They both finally completely failed.

Tom Endy

Re: Ignition System Question
 

I have a couple of the Flamethrower epoxy filled coils on my shelf. One has 5K miles on it, the other barely any at all. The first one was removed after it failed, replaced by the other one. It was removed as being suspect, replaced by another brand that has been working well for over 10K miles. I never confirmed that they were actually "bad", but I have no interest in "fixin what aint broke" at this point.

Re: Ignition System Question
 

I installed the flamethrower coil after I suspected a generic oil-filled replacement coil was failing. I keep the original coil that came on the car as a spare.

CarlG - what brand coil are you using now ?

Thanks - Jim

Re: Ignition System Question
 

My suspicion is that the wide plug probably caused the mis-fires and would not hurt the coil.

It does appear that some fellas have had bad luck with these coils lately. I've had good luck with them, but, I've had them for quite awhile. Maybe there has been a recent bad batch, maybe they're now from china. We've been having a lot of problems from china lately.

I believe there have been issues with new condensers also. I've had my share lately.

Re: Ignition System Question
 

I am using the coil that came with the FSI Zipper, even though I'm no longer using the FSI. There was no name brand on the coil, but it is working with the stock distributor just fine.

Re: Ignition System Question
 

Ditto re the Petronix Flamethrower failure.

Re: Ignition System Question
 

I just had my car back fire around 40 and stall out to the side of the road on the last ride. My pertronix coil has a cone shape to its top. The stock style rubber was causing a problem with the cone on the pertronix. The metal wire end was lose fitting which may have added to or allowed the problem to get worse. I spread the contact with a pair of needle nose pliers to archive the tightest fit possible. and did a electrical tape wrap on the cone then on to the wire to retain it and water proof it. May not be your problem but check that area. It would run fine then up over 40 back fires. If you find a rubber that fits the top better post it on the barn.

Re: Ignition System Question
 

have a question about these Flame Thrower coils. I have one but it is not marked 6 or 12 volt. Only marking is 3.0 ohm. Does anyone know if this can be used on my model A? Thanks.

Re: Ignition System Question
 

12v

Re: Ignition System Question
 

1.5 OHM for 6 volt, 3.OHM for 12 volt

Re: Ignition System Question
 

Re: Ignition System Question
 

The two coils I had was about ten years ago. They both failed early on. The first one was on my 6-volt Victoria. We were headed to Yellowstone from Los Angeles. Every time I stopped for gas north of Las Vegas with the temps around 100 degrees the car was hard to start and once started ran poorly for several miles until the temp under the hood came down. At Yellowstone it was cool and the car ran ok. On the way home it was the same drill. A few days after I got home the coil failed completely. I put the original coil back on and have not had a problem with it since.

The second car was a 12-volt 29 coupe. We were headed for Palm Springs. the first time I stopped for gas the with elevated temps the failure mode appeared. I immediately put the original coil back on. I suspect what was happening is the secondary windings expanded with heat and are poorly insulated and shorted out. When the coil cooled down the short went away (for a while).

I am a firm believer that you cannot improve on Henry's ignition design. Five million Model A's roamed the planet with it.

Tom Endy