Mine was like this!!! ur fuel metering unit could be the cause?
it might have been fiddeld with like mine...
i got some new ht leads new plugs new fuel relay, new fuel. i fucked around with the metering unit till it ideld on its own< (not ment to do this).
are all the connections on right on the back of the block i.e ur could start etc?? there was a pictured diagram on here somewhere showing how it should be.....