Hope someone can help. Ive got a ka and im in the process of putting an xr3i engine into it. Been doing the wiring today, but i cant get a spark to work when im trying to crank the engine over. So when the starter is cranking the engine, there is no spark, but as soon as i let off the key so it goes back onto the ignition, it sparks only once.

What is going wrong?

Cheers, Alex