P0302
 

Hi guys, having the p0302 misfire again on rotor number two. 04 6 Port 6-speed new coils wires and plugs. I pulled my plugs and saw that rotor one plugs are covered in carbon and dry. Rotor 2 leading is covered in carbon and dry while rotor number two trailing is covered in oil. I want to say the rotor two trailing plug is covered in oil because it's not working but are the other plugs really supposed to get so fouled so fast? Maybe it's the only plug that's working properly?

I'll attach pics after I post this because the uploader isn't working right now.https://photos.app.goo.gl/7om7baC2gBE2vKap2

First step, even if they're new they could be faulty:

https://www.rx8club.com/series-i-do-...-wires-222641/


Also, have you tried cleaning MAF and ESS; done the ESS reset or tried pulling battery for 30 mins or so to reset ECU/fuel trims?

There is a clear set of circumstances in regards to solving misfires laid out in this forum, it is literally the most talked about issue on this website. Have you exhausted all of those options?

https://www.rx8club.com/series-i-tec...t-here-222280/

You're running very rich, the plugs shouldn't be that dark. And the one clean and shiny trailing plug doesn't appear to fire at all.

Get airflow and fueltrim data from OBD.

Hi,
thanks for the reply. Ill do the coil test after work, but i tested my old coils and they seemed to be working fine.

Cleaned maf and ess. Ess reset didnt work this time around(oil pressure gauge didnt move). The battery is always disconnected since im always in the engine bay doing something but ill give it another whirl.

I went through the misfire section as well. Ill give a more detailed reply in regards to the steps i took after work.

Hi Loki Thanks,
Right! the rear rotor trailing plug looks like it gets no spark. Im suspecting the harness. Could this be related to a fuse? a fuse for the rear rotor plugs? I have torque pro. Ill see if i can do it through there?

Test your coils as I mentioned above, it's probably due to the coil not firing or a faulty wire (the HEI tester will test the coil and wire at same time). If it's not one of those then try a new spark plug again. I've had a spark plug be faulty on me before in my Tahoe where it wouldn't fire brand new after install.

If the plugs aren't firing properly than as Loki mentioned you'd be running rich due to the misfires which explains how dirty the other plugs are.

This nice part is, you have it isolated to the exact coil/plug causing the problem so should be a pretty simple diagnosis/fix.

Just replaced both coils and wires on the rear rotor. Still seems to be performing the same but i must say, all of advanced auto parts' coils look used and like crap... Im returning it again after work. I still havnt figured out how to read fuel trims and airflow in torque pro. So tired after work. Ill have to get up to speed tonight. while im at advance auto i thought id pick up this:

https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds


What do you guys think of this tester?

You would have been better off with this:

https://shop.advanceautoparts.com/p/...657/10051064-P

:confused::confused::confused:

dont really understand this data but.... I recently got the trailing plug to burn ... It looked clean... Then i bought a new trailing plug but havnt checked it yet. I should have taken a picture of the clean plug

havnt gotten the tester yet. Had a hell of a time with this car. I did get a new coil for rotor 2 trailing and a new trailing plug. I think its the wire though. above is what i could get torque to report with my cheap BT obdII scanner. Ill update regarding misfire stuff later.

You have a vacuum leak. The LTFT should be 0 and airflow should be 5ish at warm idle.

Someone in another thread went through 3 pages of this to discover that it is fixed by replacing their K&N Typhoon hot air intake with regular stock intake. Would that be your case?

replaced an omp line and had to buy a new Primary Fuel Rail Insulator (N3H1-13-158). Excited to install it. You should get a kick out of the mod I made. :lol2:

Shit, didnt see your reply! Thanks man. No I decided to stay stock before I bought my 8. I did however spray carb cleaner on the obvious points checking for idle changes ( uim ssv vdi adi hoses at air hose maf).

when i bought the 8 i used to get p0661 and 0420. after cleaning the ssv and replacing the solenoids those errors cleared. I also had to clean my maf but found that first without the aid of the obd scanner. While replacing the solenoids i found that the uim wanst on correctly. It was a major vacuum leak source.

I do have damage to the intake plastic under the front bumper but never assumed that can be a source of a vacuum leak

Maybe my evap hoses need to be checked?

can the evap be deleted?

It won't be the stuff in your bumper.... it's only a vacuum leak if it's after the MAF, anything before will still be read by the MAF.

But with that LTFT it looks like a vacuum leak (unmetered air getting into your system causing O2 sensor to read lean therefor telling PCM to dump more fuel).

Starting here

What's weird is that it shows regular AFR but the plugs are obviously very rich. Have you done the ole 20-time brake pedal stomp trick?

Will do it now, but what do you expect this should tell us?

Should I put up the data now or after the 2nd drive cycle? i get the feeling my cheap ebay bt obdii scanner f's with my pcm and so am hesitant to use it of late.

new readings since reset
Drove in stop and go traffic this morning and had rough idle all the way. 15 to 20 mile drive. The idle would drop down to 750 800rpm when idled for a few secs.
can a vfad leak affect performance?
Is it true the vfad is only for noise reduction? If so is it significant? I love the smoothe ride.

Take the data while idle. Those readings show you're coasting at 40mph and no fuel is being injected (which is normal).

how do you check the vacuum chamber on the oil filler and the oil catcher on the air hose for leaks?

ok at lunch break

Yes a leak in the VFAD actuator or Vacuum Chamber would cause a vacuum leak. A way to test it would be to disconnect the VFAD line from the UIM right behind the TB and cap the nipple on the UIM. If you problem goes away then you can assume there is a vacuum leak somewhere in the system.

750-800 RPM at idle seems pretty normal to me....

Here are the latest starting before trip during and after. I think I might have the order reversed.
https://cimg2.ibsrv.net/gimg/www.rx8...d1c9922a53.png
https://cimg3.ibsrv.net/gimg/www.rx8...9eb4c71305.png
https://cimg4.ibsrv.net/gimg/www.rx8...4eac5be46f.png
https://cimg5.ibsrv.net/gimg/www.rx8...313ae98554.png
https://cimg6.ibsrv.net/gimg/www.rx8...e998ebd5cd.png
https://cimg7.ibsrv.net/gimg/www.rx8...3d7e17cc59.png