1995 Rover 600 Problems

hi,i have a problem with car cutting out and problem starting it up after it cuts out.i have done diagnostic on ecu and it comes up with code 15-low ignition output,is there anyone that might be able to give me an idea what might be causing...

my car cuts out,usually after about 6 miles.i can restart it straight away usually with out problem.i have also had this on along journey,cuts out,starts up after a couple of attempts then have driven 50+ miles without a problem.very puzzle...