2000 Mazda 626 V6 LX

Replaced timing belt. Engine runs but rough and want to check timing. In the 'old days' a timing light did the job. Lost it, so bought a new one, inductive coupled.

Gotta admit my naivete with this engine, but when I try to run my new timing light, I get NO flashes on cylinders 1, 2, or 3, but strong steady flashes when coupled to wires for cylinders 4, 5 and 6. Since this vehicle uses the dual spark coils, I guess I'm just seeing the flashes for the wasted coil firing? Why can't I see them for the live cylinder? Never see a timing mark, gunning with 4, 5 or 6, bu that's expected. Still, the gun doesn't seem to sense the coil spark for cylinders 1, 2 or 3.

Edited to add:
I'll end this query with some new info. As mentioned, this was, I'd hoped, the final troubleshooting after replacing the timing belt. But, I'd run into this rough and unstable idling issue that was certain to be some vacuum leak? Never found a single one. But, back before I realized the timing belt was the cause of the hard engine stall, I replaced all the plugs, wires and ignition coil. No effect, of course back then. Just for the heck of it, this afternoon I decided to go back to my original parts and when I put my old ignition coil back in, the engine settled out immediately after starting up. No idle drifting and hunting! Timing light now shows timing mark right where it should be! How the heck the engine was ever running, I just can't rationalize. But something is sure messed up in that replacement coil! What's worse is that I can't figure out what the lesson was in all this!