What are the causes of Zero-Split?????
 

L1 is timed at the YELLOW ., advances normally. T1 is also at YELLOW , instead of RED like the FSM calls for.

Any thoughts???

Timing light is a Decent Craftsman. similiar to this one here

plug wires in the right places?

if you had both leadings on #1 it would do that. altough I doubt it would be running.

Plug wires are correct.

I have seen poor wires, especially low-shielded performance type wires, cause interference with one another when placed in close proximity and foul up the timing light's pickup.

The car will go to zero split just off idle. I see this above 1000RPM on my S5 turbo when the idle hangs after a decel to a stop (I need to adjust my idle settings again).

Wires are realtively new <10K Mazda OEM. Idle speed was 800. New Plugs.

Try a quick test:

When the timing light is on the leading plug you should see a pulse every 180 degrees. When you move it to the trailing plug you should see half as many pulses as they only fire every 360. This will help prove if the timing light is picking up on the leading as well as the trailing.

You might also disconnect the power plug to the leading coil (2-pin) momentarily at an idle to stop them from fireing while you monitor the trailing wire.

I think the only other thing would be the ECU. since it has the CAS imput. and then 3 outputs for each coil.

or your coil wires are shorted out in the harnes and all getting signal at once. but then each coil would probably fire 3 times per rotor which you would probbaly notice.

do you have an ign box on any of them?

maybe try bypassing it and see what happens.