I drove the car yesterday and on the 4 occasions it needed to start it did so without any issues. Today, engine turns over but won't fire. It's a 2l Zetec on TBs. No inertia switch fitted. Turn battery master switch on, ignition on and deactivate immobiliser and can hear fuel pump priming, press the starter button and engine turns over sweetly enough but won't fire. Battery is showing over 13v and about 11.3 when cranking and there is over 1/2 tank of fuel. The only odd thing (perhaps) is that I can hear a clicking under the dash when trying to start, I guess this is the problem? Likely causes anyone?