we know the spark comes from the coil after it gets a 'ground' pulse from the DME computer unit.

this ground pulse goes to the coil on the green wire. however, for the coil to do anything, it needs +12volts on the coil's small black wire...the +12v comes from the key switch in the on/run position.

test with a meter for the +12volts...turn key to ‘on’ position (oil light comes on etc)...put 12 volt tester on coil’s small black lead...12 volts yes?...then key switch is good...no?...key switch or black wire is bad.

if no spark at the plug(s) pull the high voltage wire from the middle of distributor cap and with the tester see if the spark is getting to the distributor...if you now have a good spark, your wires and/or distributor cap/rotor probably need replacing.

or if you still have no spark...make your own simulated ground pulse on that green coil wire...do this by running a home made ‘test’ wire from the chassis (or the negative battery terminal) tapping the green wire terminal with it...spark? if yes, your coil is working.

which means that the ground pulse during cranking is not reaching the coil on that green wire...very often it is a ‘flaky’ REFERENCE sensor connector, or the REFERENCE sensor itself (dirty/bent/cracked etc)...the ohm reading of the reference (and/or the speed sensor) is very close to 1k ohms (1000 ohms + or – 100 ohms)

high fuel pressure can prevent both the injectors and ignition coil from getting enough voltage...try to disconnect one of the wires to one of the injectors to see if it will run on 3 instead of 4...