I need your professional 'reading' on these Denso BR9EQ14's from my 84SE (see sig line) at 31,000 miles on these plugs:


Sorry for the size, but I'm trying to show as much detail as possible. Some additional information is that the car smokes oil a bit on startup which goes away after 5 min of driving - from what I see, this appears to be the front rotor due to the carbon buildup.

Edited to show the header, also:


What else can you tell me about rich/lean, fouling, white residue, coloring, and anything else.

I have switched to BR8EQ14's to try and run the original plugs to see if they'll help with some of the carbon. Let me know if this is moving in the right direction. Thanks!

 

Looks good.
Surprisingly little wear, considering the age.Ive always changed my plugs every 10K miles.Color also looks good.Id agree the fluff is from oil burning,but if the comsumption isnt bad and the smoke goes away,just keep driving it and dont worry.
Moving to 8's sounds like the right move.Colder,9 plugs shouldnt be needed unless your really pushing hard......and if your runnng an N/A SE engine,then your not pushing really hard.I still run stock heat range plugs in my 300HP TII engine and they all look perfect at every plug change,minus some electrode wear.

 

31K on a set of plugs!!! That's about twice the service life most of us might get. If the left ones are #1 rotor and the right #2, the rear plugs look great for the mileage. The front ones look like that is where your oil burning is coming from, which is also indicated by your header.

I have no recommendations on plugs, other than change them more often.

 

heres the link that i use to chk out my plugs hope it helps http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

 

Thanks for the link - very informative. I didn't realize I'd gone so long on these plugs until I looked back over my records. It's been so long that I couldn't remember, so I just got a set on the way home and put them in.

You've got to love a car that you can change the plugs in 15 minutes! Thanks, guys,

 

theash deposits are oil, but 31k seems it should be there. other than that. it's not too lean and not too rich.

 

Long time on standard plugs. The rear rotor is runing lean. The front rotor looks perfect but it seems to be getting pore spark. Replace wires distro cap and rotor.

 

[QUOTE=iceblue]Long time on standard plugs. The rear rotor is runing lean.[QUOTE]

Maybe a tad,in comparison with the front,but rotaries naturally run leaner on the back rotor.

 

Wrong. Only a improperly tuned motor.

 

If you run a standalone and have the ability to tune each rotor independantly,then no it wont run leaner in back.

With the factory ECU,factory sensors,factory injectors and factory manifolds,the rear rotor will run a tad leaner due to airflow and engine design.On an N/A its of no consequence,but it could be responsible for his dissimilar sparkplug appearances(besides the obvious oil deposit fluff)

 

Wrong again.

NA's as his run exceptionally rich from factory. The factory setup delivers the same amount of fuel to each rotor and fires both plugs at identical times. Helps on emissions clean up.

The manifolds are identical on each runner so one will not run leaner then the other. The factory o2 sensors are not used past I think its 1.8k RPM basically not used outside of closed loop on FI cars.

The amount of oil drizzled from the OMP is not going to cause a noticeable build up.

This is very simple he is not getting enough fuel in the rear due to aging and cloging injectors. The front is running rich simply b/c they run a little rich to begin with on factory tuning. I thought he was carbed but his sigi said GSL-SE so it is running rich from wearing wires and fouling aging plugs

 

I agree with the above. Pull the injectors, have them professionally cleaned, flowed, and tested. I'd prolly pull the whole upper mainfold and plenum and clean it out while the car is down.

 

No intake system flows perfectly even,except perhaps individual throttle bodies.
It may not be as pronounced on the SE,Im not 100% up on SE design....but TII and FD intakes have a well known habit of providing more air to rear rotors.Coupled with the rear rotor fuel cut,the rear rotors is usually the first to pop.

 

Plz stop posting your hear say false information.

The rear rotor does not have a habit of flowing more air. Please show me a flow chart to provide this information? The differences from castings and mating efforts is far within tolerance to not cause a fluctuation of AFR in the combustion chamber.

The fuel cut has absolutely nothing to do with it. The fuel cut is also perfectly safe for the car. The fuel cut of the FC and so on and all OEM cars cut all fuel to that combustion chamber or rotor. This is perfectly safe. Cutting only some fuel will result in a immediate detonation. But no EMS or ECU does this.