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MG Midget and Sprite Technical - Electronic Ignition - I'm Stupid

I have fitted electronic ignition to a number of my cars and because you can't use a bulb across the points to determine the firing point have allways had problems with the intial positioning of the distributor. After speaking to the Accuspark guys at the Classic Car Show the solution is so simple. Set No1 to TDC firing and position the distributor so the rotor is pointing to the No1 cable and the engine will start. You can then do your tweeking.

Jan T
J Targosz

If you set TDC as described and rotate the distributor (ignition on) clockwise you will hear a clack at the precise point of firing.
f pollock

I had this problem with an electronic distributor from Minispares. Apparently, it depends on what sort of magnetic detector is used. The one I bought from Minispares had a magnet with peaks at the 4 firing points. On an Accuspark I also tried the magnet was perfectly round unlike the Minispares one.
With the Minispares one there was no way to get it to trigger by rotating the body through the firing point but with the Accuspark there was.
The Minispares one was OK when it started rotating so it's pickup needed movement to trigger. The Accuspark one didn't need movement, it just needed to be near the detector in a particular position.

Also, in the past I've used an old (MW/LW) transistor radio set nearby to detect the spark. It worked a treat in the days when points were the norm.
Rob

MG Moneypit

I was able to use either a volt meter or a 12v bulb with an Aldon, and this one that I had on my Capri, that I was told was a Simon bbc.

I don't like electronic, so reverted to points on both my Sprite, and the Capri before I sold it.

And this miniforum discussion link says the same.

"-- assume your Simon BBC kit is like the PowerSpark or AccuSpark setups... an add-on module that attaches to the the breaker plate with two wires (red and black) going from the distributor to coil (+) and coil (-) respectively. Is that correct? If so, you static time almost exactly the same as you do with points.--".

https://www.theminiforum.co.uk/forums/topic/293550-how-do-you-set-static-timing-with-electronic-ignition/





anamnesis

I use the off-station radio method and listen for the click. It obviously works with points on the Frogeye. Butt I also use it with my 1971 car which uses an MG Metro electronic dizzy with a little plug in module. Not knowing about how these work it hadnt occurred to me that it might not click on the radio. But it does!
GuyW

The lamp bulb and radio click will work with conventional points but not with many types of electronic ignition. The distributor needs to to turning fast to trigger a spark. Simply turning the body by hand with a stationary engine will not produce a spark.

Jan T
J Targosz

No doubt true on some, but definitely not all.

What's min' rpm to trigger? Sounds like an almost flat battery could cause a problem too then, as it turns the engine slowly. Whereas, even with an almost flat batt' on points, I've been able to start.
anamnesis

You certainly don't have to spin it to create the radio interference 'click'. I just twist the dizzy body slowly back and forth by hand to locate the exact spark point.
GuyW

The 123 Distributor has an LED, you simply rotate the dizzy until the LED lights up and then back it off a fraction until it goes out. You are then set up, very easy.
Chris Madge

The accuspark type in the pics above, you can see the magnet is perfectly round. I believe this type uses a Hall effect which triggers when it detects a magnetic field of a certain strength. Movement is not required for this type so it doesn't have a minimum rpm limit.
The other type (the one I have from Minispares) has very defined peaks (like arrow heads) at the 4 firing points and I believe it uses an induction coil as a pickup. Coils, of course, require a moving magnetic field to induce a current, the faster the change in magnetic field the higher the induced current. This type does have a minimum rpm to work.
Rob
MG Moneypit

This thread was discussed between 12/11/2023 and 16/11/2023

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