My 83 Rx-7 wouldn't start so I pulled the plugs and they all have spark but only two at a time, when I switch the leading and trailing wires from the coils to the distributor cap both the trailing spark plug wires work but if I switch it back only the leading spark plug wires work. I don't know whats happening it started and ran fine before this happened.

 

I had a no-start prob once as well. Checked the plugs: they sparked so I moved on, changing out just about EVERY part of the ignition system. Nothin'.
So I took another look at the plugs. Swapped in a new set:
BOOM!
off to the races. So just because the 'spark' doesn't mean they are OK. Easy to test my theory

Stu A
80GS
AZ