Correct coil for Magnetronic Lumenition in a Sprint.

[gmsclassics]

I’ve run the same unit as yours in my Pageant Sprint for a dozen years now and covered 25k miles without issue. I also used one in my racecar for an equal length of time.

If the coil you have came with a resistor and instructions say use that or the existing in car wiring (white/pink wire and white/yellow wires both to +ve on coil) then it needs to be used – and that is the standard setup for a Sprint.
So, under normal running the white/pink wire (the resistor wire) reduces the voltage feeding the coil, which is nominally a 6v one although usually marked as a ‘12v resistor coil’. When you are cranking the starter motor over, the white/yellow wire feeds the coil – the high current draw by the starter motor turning the engine over reduces the voltage throughout the electrical system so feeding this wire direct helps the coil produce a good spark to start the car. This wire stops supplying current when the starter disengages.

The white/slate wire from the -ve on the coil feeds the rev counter.

I have connected the red wire from the Magnetronic unit to the fused side of the ignition fed side of the standard fuse box (where the green wires connect in). If I read your description correctly I think you have connected it differently? The black wire from the Magnetronic unit is attached to the -ve side of the coil (same as white/slate wire).

Try that and see how you go. You probably need to check the ignition timing too - I suggest you try 10 degrees BTDC as a first point. Clean plugs too. I use NGK BPR6EFS and you can gap them at 30 thou when using electronic ignition rather than points.

Geoff

[GinettaG15]

just an advice to the plugs you mentioned:

BPR6EFS

the R stays for "resistance"

for certain reasons (noise suppression mainly) one of the components in the igntion system should be "R"-Type.
one, and only one!!!

all modern HT-Leads already are R-Type...so in combination with modern HT-Leads you should fit e.g. BP6EFS.
otherwise you have 2 items in the iginition circuit with resistance : PLug& Lead