I'VE ONLY BLOODY FIXED IT !!! with thanks to the guys on this site. But Kevin gets the gold star as it was a short on the main injector loom.
Some muppet in the past has worked on it and pushed the injector loom between the top of the bulkhead and the windscreen wiper linkage

so over time it has steadily worn through and shorted four of the wires ( I even took a piccy)
So after some quite daring (for me) spanner work I found the fault and phoned my best mate Jay who is an auto electrician and he then repaired the wires and we got it put back together before dark

It runs great, the warning light has gone out , and it has been slowly burning/ evaporating all that fuel that was in the exhaust with a lovely smell.
Thanks again to all who replied. Credit to a great site !