Did a conversion from points to a later model brumby's electronic pointless disty today. I got the new distributor a long time ago to replace the one in the wagon as the wagons was pretty flogged out and its vac diaphragm was shot. When I first got it I didn't want to mess around with changing to electronic ignition so I just swapped the guts around and put the points into the new disty body with the good diaphragm and better bushes.
~20000kms later and the points and the points are shot
. Hats off to them though as they are grandad age in point years.
Anyhow, occurred to me yesterday that I still had all the bits from the new disty. So I pulled it all out and assembled it. Here it is in my old disty body,
But how do I wire it up? had a quick google of the part number it, found a dinky little photo, wired it up on the bench and gave it a flick,
Hmmmmm yummy, but wait!? isn't this meant to be a reluctor setup? that square wave output reeks of hall sensor. Yep definitely a hall sensor setup.
For those interested there is very little difference when it comes to hall sensors and reluctors. Both use some form of coil with a magnet. The difference is in the waveform they output.
So, got the disty sorted, now to make a controller to drive the coil....Turns out altronics carry a kit for electronic ignition. Beauty!
Sorry didn't take any pic's off assembling the pcb but I did take a few of it finished.
Basically it consists of a large high voltage MOSFET to switch the coil to ground, some basic analog circuits to control dwell and debounce and then it supports around 6 different trigger signal types and you populate the parts for the trigger your car uses. I chose hall sensor as that's what was coming out of the disty.
I didn't have any little crimps for inside the disty so I Opted to solder some flying leads onto it with external connectors.
Did some tidying up of the wires, tucked the ignition module inside its dinky little box and screwed it into the wheel well under the coil.
Set the timing, job done. As far as improvement goes over the old points, Ignition timing is 10 fold less jumpy. Its more stable then the old ea82 MPFI in the vortex that's for sure. I doubt there was even half a degree (+/-) of drift or erratic behaviour. Idle quality along with cold running quality have dramatically improved. Seat of the pants feel on the road isn't that much different. Maybe slightly smoother but most likely inside my head.
Pretty good upgrade for those who are chasing the pinnacle of reliability in there Subie!
Regards
Doug
. Makes for absolutely beautiful idle. I didn't try spinning the reluctor the other way. Did you want me to capture some waveforms and compair? I would emagine it will ring more with it the other way around.