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-   -   Read my spark plugs - running rich, heavy fouling (https://www.rx8club.com/series-ii-technical-trouble-shooting-160/read-my-spark-plugs-running-rich-heavy-fouling-267737/)

Blue2010R3 05-17-2018 12:12 PM

Read my spark plugs - running rich, heavy fouling
 
3 Attachment(s)
I had the same (though less pronounced) ticking noise as shown in this video.

Members of this forum suggested I change the spark plug wires, which I had my dealer perform with Racing Beat wires. (This did not solve the ticking.)

The dealer wrote in the notes (this dealer doesn't bother to explain much) that my "rotor 1 leading plug is missing tip" so I ordered a new one to replace it. When I pulled the original plug, I noticed a ton of fouling and carbon build up after just 5,000 miles.

The engine feels strong and doesn't have any issues starting. I had experience some wobble/dying at idle a few months back when my battery was constantly being discharged due to a faulty alternator, but haven't experienced it since. My gas mileage has always been piss poor (I rarely get over 15 mpg), but I attributed that to aggressive driving and just the design of the rotary engine.

Compression test from 59k miles (now at 65k) also included. Any ideas?

UnknownJinX 05-17-2018 12:54 PM

My looked kinda gross after 10k miles, but not as bad as yours.

Which coils were you using?

Also, when you say you are running rich, have you looked at your LTFT and STFT?

Blue2010R3 05-17-2018 01:00 PM

OEM ignition coils, replaced 4/16 (under 6k miles ago).
I have not performed any tests to verify I am running rich-- just my own conclusion from the plugs.

Loki 05-17-2018 01:15 PM

Do you have an OBD reader and can you check your fuel trims (STFT, LTFT) on a warm idle.
90% of rich conditions are just vacuum leaks.

strokercharged95gt 05-17-2018 04:48 PM

does the tick increase with RPM? I dont think it has much to do with spark, because even at say 1,000 rpm idle each plug would be firing at 48x per second which is way faster than that tick. Is it louder on the exhaust side or plug side?

Blue2010R3 05-17-2018 04:51 PM

In terms of volume, no-- the engine noise drowns it out above ~ 1500 RPM.
In terms of frequency I can't tell due to the above.

Thanks,

strokercharged95gt 05-17-2018 05:01 PM

It sounds like an exhaust leak of sorts. I would jack the front end way up (along with the back) and probe droid around all sides of the motor and try to pinpoint where you can hear the loudest ticking noise from. Harbor freight sells a mechanics stethoscope for $4.

Blue2010R3 05-23-2018 11:23 PM

4 Attachment(s)
Here are some STFT and LTFT reads from my Torque app at 0 and 2500 RPM. Not sure if this is helpful at all.

Images are rotated but here is the readout:

Idle (804 RPM):
STFT: +3.1%
LTFT: +1.6%

@ ~2500 RPM:
STFT: 0.0%
LTFT: +1.6%

Blue2010R3 05-23-2018 11:28 PM

And here is a link to a video I took today showing the pronounced clicking.
https://1drv.ms/v/s!Avww3gBnZPRbylCYK5vXc25-lPkZ

Notice that Rotor 1 Lead Spark Plug wire "jumping".... perplexing as all hell.

Loki 05-24-2018 07:30 AM

Fuel trims look good
Spark plug wires are a bit of a weird thing to recommend on thrir own, but that missing electrode is probably not good for the coil attached to that spark plug. Do you have a coil you xan replace it with to test?

Also that electrode is somewhere, potentially in the engine. I'm not sure what can be done to get it out, but it could have caused internal damage.

The frequency sounds in line with spark ignition at idle. Spark plugs fire 13x a second on a 800rpm idle, which matches the sound imo.

BluSpectre 07-18-2021 12:24 PM

My car has been idling rough and rich, and my OBD II tool reads my fuel trim to be anywhere from 3.5 to 5.0 . I didn't think anything of it, but when I removed my rather new plugs for deflooding they were very blackened. I also have my older plugs that I changed when I did my coils, and they didn't look excessively worn or blackened. Interesting...

Tharinda 08-03-2021 03:18 PM

https://cimg3.ibsrv.net/gimg/www.rx8...3d84815858.jpg
This is what got in my 2009 S2-R3, can someone please tell me if there is anything wrong here. It smells lot of gas at start up but later it seems fine. But there is lot carbon build in the exhaust.
This is a idle, are the fuel readings within spec? MAF reading?

Loki 08-03-2021 04:30 PM

Looks OK. The fuel trims are a bit weird but the airflow for the rpm looks right.
Smelling fuel on startup before the cat has warmed up is normal. Lots of soot in the exhaust indicates the car was driven in low regimes and needs to be driven like a proper sports car more often. These cars do NOT do well if granny-driven.

However, before you go beating on it, confirm that your catalytic converter is in good shape internally and that your ignition is healthy. rx8help.com will give you the background you need.

Becky245 08-13-2021 05:11 AM

i am finding it difficult to get original NGK plugs here, plenty of fake ones around.

Recently got a set from the island of Cyprus, not sure if they are genuine, $110 for a set, plus $20 shipping. They look identical to the original ones swapped from the engine, resistance test is in spec.


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