hey i copped this with my 4ac.
if you know that you're power wire is the right one from the loom then i would suggest checking that the earth wire from the coil is wired to the right place...
on the 4ac it gets wired to a screw on the distributor coz thats where it gets it timing from...
i dunno if the 4age is wired the same but check it out (try wiring the earth from your coil to you distributor if there is provision for it) or if someone can back me up or say this is wrong?