RX7 3 Gen Misfire
 

Hi all. My 1993 3 gen RX7 has a misfire past about 4000 rpm. I'm assuming it's ignition based, but not sure what typically causes misfiring on the RX7, or how to test coil packs/igniters in case the problem lies there (boy they're expensive!). Plugs are new, new plug leads on the way

I'd appreciate any advice, help, and guidance you can give to point me in the right direction and get this beautiful car purring again.

Thanks

Ian

First, I'd be sure you're dealing with ignition vs. something related to the engine or boost. It's my understanding that ignition tends to occur based on RPM alone, and engine/boost problems only occur when there is enough load present as well as RPM.

Do you have any engine codes? When did it start cutting out?

As for ignition issues, the plugs, plug wires, should be in good shape. Sometimes the ignition coil harness develops a short. Used coils are quite cheap - I'd personally prefer to buy two sets of used ones before buying any new coils from Mazda.

Dave

Misfire
 

Dave

Thanks very much for your reply.

Difficult to tell whether it's ignition or fuel based. It definitely comes in around 4000rpm, and I'm not sure how to test for either problem. Completely agree with cost of coils, but looking to elimiate each potential source and not sure how to do this. I've read threads involving ignition and injectors - even petrol fiters - so I'm eliminating one thing at a time.

Any pointers you may have would really help.

Thanks again

Ian