Ignition problems

[David Wright]

I have been tasked with trying to sort out a problem on a c3 100 quattro turbo (MC engine).It has previously had an immobiliser fitted and that has been now removed.The problem is that I can only get an ignition spark at the king lead out of the coil for about 1 or 2 seconds,then it disappears.

I have done as many checks as I can on coil,rpm pickup,crank position sensor,dizzy,and have pinned out as many connections back to the ecu from all these units as I can.I guess all the systems must work to give a spark,but why does it bugger off like that?

Any ideas gratefully received before I send the ecu off for testing.

Many thanks, Dave