That idea did not work due to the new tacho would not read reliably the existing sensor on the pump pully, might be because it see's 3 pulses per 1 crank rev, (6 webs on the pully) so bought a digital one that has a hall effect sensor and comes with a magnet, mounted that on the plastic timing belt cover with 2 magnets on the camshaft pully, works a treat, not quite so easy to read but good enough, Rick