Technical 123 ignition distributor

[Nedsly]

I bought my 500l at an auction and it had an aftermarket distributor made by " 123 Ignition". Very high quality but I am starting to think it is causing a series of misfires (5 or 6) after the car had run about 5 minutes. The misfires then stop . Anybody have any idea what this might be. One theory is that when the battery is finally fully charged after the start the voltage regulator switches over and in the process delivers a voltage spike that puts the computerized distributor into protection mode for a split second. I am ready to believe it as I have checked everything else several times. Thanks, Nedsly

 

[fiat500]

I bought my 500l at an auction and it had an aftermarket distributor made by " 123 Ignition". Very high quality but I am starting to think it is causing a series of misfires (5 or 6) after the car had run about 5 minutes. The misfires then stop . Anybody have any idea what this might be. One theory is that when the battery is finally fully charged after the start the voltage regulator switches over and in the process delivers a voltage spike that puts the computerized distributor into protection mode for a split second. I am ready to believe it as I have checked everything else several times. Thanks, Nedsly

I would have a very careful look at the wires that exit through a grommet in the side of the distributor. The insulation can crack or split just there as there is no lateral support of the wires.
I also had problems with excessive free-movement of the shaft which resulted in the rotor-arm making contact ith the inside of the distributor-cap.
I admit that I am biased against the 123 for the Fiat 500 because of poor build quality and non-existent manufacturer siupport.

 

[JumpJet]

They look fancy, but they're garbage and don't stand up to the heat of the engine bay. When they get hot, they start to misfire randomly. Your best bet for long term reliability is to go back to a points setup with a quality condensor or get a lost spark setup that came on the later 126s.

 

[the hobbler]

They look fancy, but they're garbage and don't stand up to the heat of the engine bay. When they get hot, they start to misfire randomly. Your best bet for long term reliability is to go back to a points setup with a quality condensor or get a lost spark setup that came on the later 126s.

All 'electronic' ignition systems used on the 500/126 engines that utilise the distributor are prone to one major fault----heat. The 'cooling' air blown over the engine then blows over the distributor, and it is often in excess of 100 C, the "wilt" point for the electronic ignitions (and, 'pattern' condensors). As 'Jump-jet' suggested, go back to 'points' and fit one of the 'competition' condensors (Swiftune or Shacktune) which can be fitted up by the coil---they have long 'feed' wires AND long 'earth' wires.