Electronic dizzy problems

[Ke70]

I have just put an electronic dizzy in my ke70.It is the internal ignitor type dizzy. but have one slight problem.I have wired it in but when starting the car now i have to hold the key on to keep the car going.I had the same problem when i had the points dizzy and fixed the prblem by fitting a new ballast resistor.I have tried fitting one now but still hasnt fixed the problem!!Any ideas please??I may have the wiring wrong(only two wires need wiring)So maybe if someone told me exactly where the wires went it might fix it.
cheers
Myles