Hi mate,
Check those dam phase sensor wires for cracking first, Cosworths of this age 99% of the time have crumbly/cracked insulation on the wires.
You did the job of changing the crank sensor fine, just double check that the lugs are all present on the crank pulley and are all the same height and feeler gauge the new sensor, should be between .60mm if i recall correctly, check the specs in the workshop manual though. Any lug on the pulley is fine seeing as they are all the same.
The phase sensor 'phases' the injection timing at higher rpm.
If possible also check the fuel pressure from the pump and check that the fpr's diaphram isn't holed and that it actually raises the fuel pressure under turbo boost.
Check also the phase sensor's gap with a .30mm feeler gauge and while your there the cap and rotor arm for burning/tracking and other damage.
Gap your plugs accordingly.