I had a Mazda GLC that would only run with the ignition advanced way
more than normal. Replaced the plugs, wires, rotor, distributer cap.
No help. It turned out that the original rotor had a hairline crack in
it that would allow the spark to travel through when the spark
resistance got too high. The replacement rotor had the same exact
problem. I finally diagnosed it with a timing light. With the light on
a spark plug wire it would flash until the timing was adjusted to
normal. Then the engine would die and the timing light would cease
flashing. But with the timing light pickup on the coil lead it would
flash when the engine was cranking even though the engine wouldn't
start. So I figured the car was losing spark in the distributer and
this was happening because at normal timing the charge in the cylinder
was more compressed and so the resistance was much higher than when
the timing was advanced and the cylinder pressure lower. It took me a
couple weeks to finally figure out what was going on. I bought another
rotor, a different brand, and it solved the problem.
Eric