Shortly after gassing up and cruising at about 70 mph, my Fiat 124 Spider misfired, backfired and stalled out. When that has happened in the past it has been because of an over-heated ignition coil. I carry an extra and when I have replaced it, the car starts immediately and runs well. This time, not. Had to get a tow home. The car will start and run for a few moments, misfire, with the tach jumping, and stall and refuse to start for some time. The battery charge indicator does not come on when the key is on, however, the battery seems to be holding a good charge. I've used dry-gas just to make sure the recent fill-up wasn't at fault and have put in a new coil. Any suggested diagnoses would be appreciated.

My Spider, a '77 which has the dual-points distributor, had the same problem. I replaced the points and condensors and it ran fine but was somewhat hard to start. I later easily replaced the points with Pertronix electronic ignition which essentially just screwed into place in my original distributor. The car runs great and starts immediately at the first touch of the key.

Thanks Laurence,
that's good to know,
steve y may get back to us with an update

After much investigation, I discovered that the fuel pump, which I thought after 24 years had gone bad, was actually suffering from a voltage drop which resulted in a lack of sufficient pressure to feed the carburetor. The source was the ignition switch. I've replaced the ignition switch and the car runs fine now.

I have a '77 124 spider and would be interested in knowing the brand of the electronic ignition and if there is a website that sells them. Thanks in advance.

Charlie124 said:

I have a '77 124 spider and would be interested in knowing the brand of the electronic ignition and if there is a website that sells them. Thanks in advance.

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PerTronix at www.pertronix.com
or maybe www.summitracing.com

There's probably other makes available.

Imho, the standard points controlled ignition system works fine if correctly maintained. I know lots of members here wouldn't agree.... but to each, his/her own.

Al.

F123C said:

PerTronix at www.pertronix.com
or maybe www.summitracing.com

There's probably other makes available.

Imho, the standard points controlled ignition system works fine if correctly maintained. I know lots of members here wouldn't agree.... but to each, his/her own.

Al.

Click to expand...

The points, and the contacts inside the distributer cap, show evidence of significant sparking. What is the correct maintenance for them?

Charlie124 said:

The points, and the contacts inside the distributer cap, show evidence of significant sparking. What is the correct maintenance for them?

Click to expand...

If the CB points are arcing, it could be caused by a faulty condenser or a faulty (or wrong) ignition coil. Resistance specifications for the Spider points and electronic ignition coils are below. If someone has fitted a low primary resistance electronic ignition coil to a points ignition system, that would cause arcing of the points. You will need a good quality ohmmeter to measure such low primary resistances.

Easiest way to test the condenser is by substitution with a known good one.

Points coil resistances: Primary; 2.59Ω - 2.95Ω. Secondary: 6750Ω - 8500Ω.
Electronic coil resistances: Primary 0.75Ω - 0.81Ω. Secondary; 10,000Ω - 11,000Ω.

See this thread: https://www.fiatforum.com/124-spider/316488-fiat-124-ignition-coils-failing.html
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