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Showing content with the highest reputation on 12/06/2018 in all areas

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    Hi Jasper, I would strongly suggest, if you are going to head into programmable ignition, that you seriously consider another kind of trigger, rather than just using points. Points really suck, when used in this precise application. The rubbing block wears, & the cam lobes in the dizzy wear, providing slightly different timing for each trigger. Oh, & they have a habit of bouncing/oscillating at high revs. On top of that, you have to keep the points "wet", by passing a reasonable current through them. Not enough to arc, but enough to get a good clean signal. >100mA. The reason for this, is to "burn off" the very thin film of oil vapour that builds up inside the dizzy, & on the points contact surfaces. I would strongly advise using a non contact system, such as the Accuspark, or maybe a K Series electronic dizzy with VR sensor, as Dave has suggested. The only trouble with VR electronic dizzies is, that their output is dependent on RPM, and when you are cranking, the output of the trigger, is at it's lowest. VR sensor wires are also polarised. Does not work very well, if wired in reverse. There are two kinds of K Series electronic dizzies. Those with VR sensor only, & those with a VR sensor plus an in-built electronic ignitor. The model with built-in electronic ignitor is the better one, as you simply connect the output wire to a 100 ohm, 10 Watt resistor, the other end of which is connected to +12V ignition circuit. You then get a nice square 12 volt trigger pulse out of the dizzy, to feed to your ECU. Even if you can get hold of a K Series dizzy with VR sensor, but no built-in ignitor, you can grab a Bosch BIM024 module, as Dave has suggested, & attach the above mentioned 100 ohm resistor to the BIM024 coil connections. I ran one of those for several years, without issues. The advantage of the Accuspark is, that being a Hall Effect device, it gives the same output amplitude, irrespective of the RPM. All electronic programmable ignition systems, needs a MAP sensor, so you can dispense with the vacuum advance/retard device. However, you will need to dissemble the dizzy, & remove all the bob weights & springs, & then lock the shafts up, so all advance & retard, comes from the programmable ECU. The dizzy, then becomes simply a trigger device, & distributor of the HV to each spark plug. The Accuspark has another advantage, as you can use it directly to get the engine started, & then switch automatically to programmable ECU, as soon as the ignition key comes back to the "run" position. The very best K series dizzy, that I found, to create a source for electronic trigger pulses, is the 3K Denso model, with the Octane adjuster knob. This dizzy is the physically smallest of the K series dizzies. Accuspark do a module for it specifically. They are very easy to "lock up", & remove the vacuum advance unit. I actually made one up for an experiment a week ago. Took me all of 1 hour. 3mm roll pin was all I needed. Hope that assists your decision. Let us know how you are going to trigger the ECU, then I'll give you suggested options for ECU. Cheers Banjo