New dizzy only starts when key released

[buteux]

I hope someone can help, I have recently fitted an aftermarket replacement dizzy to replace the previous owners points one from a bay. I had to get a loom for the coil to ignition unit and dizzy plug. The timing seems ok, it runs very smooth, ... when starting it turns over but I have to release the key before it will fire. I suspect its the wiring, I have one loose brown lead from the loom which I assumed was an earth and connectdd it to van body. Any tips or expln of where this wire should attach most welcome!

[peteabbott]

Don,t realy know if this applies but.............on starting because the starter drops the battery voltage you have a 9v coil so on starting the coil has what is left in the battery ( 9V ?) When you release the key a resistor is bought in line dropping the voltage to 9 V when the engine runs. So yes it seems you have a wiring problem. I just cannot remember but I think there are two wires on one of the coil posts, one that comes from start position on the ignition switch and the other that comes from the run position on the ignition switch through a "ballast" ? resistor to maintain 9 V when normal running. Please correct me someone if I have got this wrong and I hope this helps mate. Sounds like the wire from the ig switch is missing ?

[buteux]

Cheers, i will have a look today if the rain stays away. I'm not convinced the timing is perfect as it feels underpowered, I have done it with a strobe etc. I noticed that my extra brown lead doesn't seem to be represented on the drawing of the unit in the Haynes manual, i don't have a stabilising unit either. If i get to the bottom of this i will report back.