P0302 Cylinder Misfire

Capncorroded

Just to follow this up - Dealer confirmed the ECM failed. (as I kind of expected)

there was no reason why they could find. Dam electrical stuff.

Cyber370

Today's so-called automobile technicians simply replace the ECM anytime they can't find the true cause of an electrical gremlin. By them saying they don't know why it failed says it all. If I had my ECM fail, I would definitely want to know why to avoid it failing again.

With such low mileage I find it hard to believe your ECM failed unless you've been storing it outside under a tarp all winter or a place with very high humidity OR your car was a flood damaged salvage car.

I always keep my car hooked up to a battery maintainer when not used for longer than a week. Today's car electronics require a fully charged battery at all times.

__________________
"That’s when you know you’ve found somebody special. When you can just shut the f*ck up for a minute and comfortably enjoy the silence.”-Mia (Pulp Fiction)

Capncorroded

Car is stored in a clean heated garage, low humidity for CNY in the winter, was def not a flood/salvaged car, and no signs of rodents or anything. The day before, I even started it up and pulled it out to turn it around and it was fine- then boom, all sorts of issues.

Being an HVAC technician myself, I have to deal with loads of control boards, miles of wiring, various sensors, harnesses etc, and have had multiple situations where I have had to replace control boards without a direct reason of why the board failed - Do I like that? nope, not at all. I def want to know what happened so it doesn't happen again, but sometimes it is what it is.

Hug0

Hi everyone, I am tracking down similar problem with my 2009 370Z with Uprev and exhaust, intake, etc.. 160 000km

Couple weeks ago car started turning off fourth cylinder. It was after cca 15km drive and only mornings (around 5°C). After Turning off engine, error was gone.

Than it runs normally for couple days. Than again same error. And again, just turn off engine and everything was normal after new start.
There was no error codes.

After week, I finally read codes on running engine and it was P0304 cylinder misfire.
Than sometimes turning off engine does not help.

So I changed all spark plugs and move coil from 4 to cylinder 2.

After that, I am running on five cylinders all the time. Same error code.
I tried spark with coil and spark plug from another cylinder and there is no spark on cylinder four.

on coil sockets there are three wires, one is 12V when ignition is on, second one is ground and on third one I found some readings with multimeter cca 0,6-1,2V in impulses when starting engine. But I am really don´t know if its correct or not.

Also I changed left cam sensor for right one, still same problem.

I really hope its not dying ECU..

Uprev and everything else was there before this problem and worked well.

Any ideas, please?