Polo GT twin dellorto carb conversion Ignition HELP

Hi all,Ok so my car has a polo GT engine conversion, i'v decided to go down the twin dellorto 40 route. Im far on in the conversion now. So im having some trouble with the ignition and spark. Im using a mk2 golf electronic ignition module and loom from a 1.3, the dizzy i has i bought off someone who planned on doing the same thing im doing, so it's a mk2 golf 1.3 dizzy with the vac advance taken out, re weighted inside and balanced. There is NO vacume take off on my inlet manifold and NO vacume on my carb as they are the old DHLA 40's without vacume. So no vacume is my only option. It's all wired up after alot of messing about we managed to get it to crank over and we now have spark. It sparks and runs for around 5 seconds or so, then after that there is no spark and the engine dies even with throttle. It's asif it's being shorted out and the spark going after a few seconds. Surely the distributor cant be faulty otherwise it wouldent spark at all, am i right? I'll be changing the leads, cap and rotor arm once i pick up the parts tomorrow to see if that helps at all. What else would cause this problem, would bad earth make it happen? Another big question is the earth from the dizzy, where does it go?? whenever we connect the earth we loose all spark and it wont even start at all! Need help asap really, any help would be much appreciated!