Misfire on Cylinder 2

[Alexpb2401]

Car started horribly. Felt a lot of vibration from the engine and was not making a nice sound then cut out and wouldn't restart.

My code reader was at friends house so had to call the AA. He managed to start it and after some hard revving and a bit of dark smoke coming out the exhaust it was working again.

Error code was 'P0302 Cylinder 2 Misfire'

Any suggestions my learned friends?

[PaulAV]

I would check connections for the rear coils, leads and spark plugs when looking from the front, if you have no recent record for replacement of coils, leads and plugs, then you probably want to invest in a full set of each.
It's also worth checking your maf sensor and eccentric shaft sensor are clean and look for an oil burp in the air intakes

[Alexpb2401]

I would check connections for the rear coils, leads and spark plugs when looking from the front, if you have no recent record for replacement of coils, leads and plugs, then you probably want to invest in a full set of each.
It's also worth checking your maf sensor and eccentric shaft sensor are clean and look for an oil burp in the air intakes

Had new coils, leads and plugs less than 12 months ago

[warpc0il]

Purchased from...

[Alexpb2401]

Rotary revs. Mazda C Coils with Mancor leads

[PaulAV]

Then as stated, check connections, check intake, you may of had an oil burp (although its showing cylinder 2 misfire it may only of picked up a misfire on cylinder 2 at the time) look for any wires that have worn and check to see if any plugs are fouls.
Clear the cel and see if anything comes back

[warpc0il]

It's not impossible to have a genuine coil , lead or plug fail early (Google - reliability bathtub curve) but much less likely than those from dodgy sources.

A failed trailing coil (on it's own) wouldn't cause a misfire, so if it's ignition then start with the leading set (coil, lead, plug)

It could be a problem with a fuel injector (or it's wiring) as the PCM detects "misfires" as uneven power pulses, so anything that could cause the rear rotor to not be running cleanly is a potential suspect.

The Eccentric Shaft Sensor and/or MAF are also possible but less likely to only impact the rear rotor - the PCM has three different codes to choose from;
- P0300 Random misfires
- P0301 Front Misfire
- P0302 Rear Misfire

[njkmr]

Had same with nearly new coils.
Two of them had failed.
Replaced by Rotary Revs no bother.
It can happen so it would be my first check to be honest.

[V8 Power]

I had an issue where mine started and ran on one rotor. It was down to a loose coil harness plug.
Re seated and all cured.

[Alexpb2401]

It came back today. Same horrible start, lumpy and not running properly. Took quite a few attempts to restart then was ok...

[osman]

I had something similar
Rear rotor lost compression on 2 faces, get a compression test done

[njkmr]

You had the coils checked yet?

[Alexpb2401]

No. To be honest, I did nothing (which is why it’s happened again) was hoping it was an anomaly.

Going to hopefully check all connections and plugs today. Really hoping it’s not a compression issue

[warpc0il]

Don't forget to also check fuel injector and ESS connections as "misfires" don't relate directly to ignition.

[SprintRX8]

Try swapping the coils leads and plugs over.
So in theory changing between the two rotors.
Then see if the problem has moved to the other rotor chamber.

[warpc0il]

If this "fixes" the problem then it was either a dirty/loose connection, that is now sorted, or it was a duff leading coil which is now a trailing coil, which doesn't trigger a misfire but can still kill the engine and/or cat.