Ignition Upgrade Time...

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e34pilot
Newbee
Posts: 1
Joined: Sun Jun 15, 2025 1:30 am
My E21(s): 1983 320iS

Ignition Upgrade Time...

Post by e34pilot »

I've been putting off replacing some of my worn out ignition components for a few years now and am finally thinking about doing it.

I recently saw an '02 run with a perfectly steady idle by making use of an ignition box connected to a custom crank sensor which was very interesting. I assume I could do something similar on my '83 320iS however I know my wiring might be a little more complex because of the factory electronic ignition etc.

If I was to do this kind of upgrade with an external ignition box that manages timing, multi-spark etc., I would need to know how the factory EFI and tach got their ignition signal from the factory distributor so that I could somehow derive a similar signal from the ignition box. After all, I'm not going to get far with the EFI and even if I did, I wouldn't enjoy the ride as much without a tach.

Does anyone know how the EFI/tach get their signals on the factory setup? Anyone gone the full crank sensor route with an ignition box and had success? Would like to hear how you went about it.


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nic65
Upcoming E21 fanatic
Posts: 174
Joined: Tue Sep 18, 2018 2:12 pm

Re: Ignition Upgrade Time...

Post by nic65 »

la tua 320 dovrebbe già avere la accensione elettronica, la 02 aveva i contatti col condensatore
Wilmo
E21 Mad
Posts: 1983
Joined: Thu Jun 30, 2011 8:35 pm

Re: Ignition Upgrade Time...

Post by Wilmo »

With a modern EFI like the Microsquirt you can control the tach as well. And the rest.

I started this way back in 2017. Took a VAG ignition box and continued with carbs. More than a year later the first injection followed and after that by individual throttle bodies. I like the reliability, the performance and it was a great journey learning a lot about engines. It was totally worth it.
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