One thing I did to aid starting and increase plug life was to switch from the OE coils to Accel

Superstocks and I ditched the NGK's for Autolite "side gap" plugs(I think# 2926)Living in Maine it's gotta deal with

some extreme temp variables.If it only fired on 1 rotor,chances are either an ignitor or coils to blame.

(I'm assuming you DON'T have points...if you do,get a OE CDI setup,quick!)

Happy hunting,PeterB

guys,

if its only firing on one rotor it cant be the coils as one coil is for leading spark the other for trailing. If one of the coils was on its way out you would either have leading spark on both, where upon the motor would run ok or trailing spark only on both and the motor would run like total ****, if at all.

swap your coils and see what happens.. <and make

sure they are hooked up good. Next, take a spare spark plug and hook a plug wire to it to a ground and check for spark when someone is cranking the engine. do this will all of the wires. Also make sure your distrubuter is good, check the

distrubuter's rotor connection points to see if its somehow damaged or the cap. Also see if the plug wires have good

resistance values!!!!!

Next, if that stuff doesn't help, you may need to figure out if your compression is good somehow. Mazda compression checks are not cheap. If you have a cracked apex seal it would run very rough through out the rpm, I know this happend once to me when I bought a cheap junkyard engine and it worked perfect for a week and then the apex seal broke and still ran till piece broke loose and locked the engine tight. Luckly it happened right in my driveway. Went from 2000rpm to 0rpm in a instantly!!!