Ruthenium plugs

[IndianaDIY]

I have a 4cyl engine.
From the passenger side, two plugs were installed with a brand new Denso ignition coil last October(I think these are cylinders 1 and 2). Two were left with the old originals; these were closest to the driver side. I kept two of the old ignition coils from 1 and 2. Cylinder three tossed a misfire a month or two ago, but it was misfiring before that. 4 I believe was questionable.

So, I put one of the original ignition coils from 1 or 2 into 3. 3's "hole grip" was totally gone. There was no feeling that it was tight enough to latch on to the stick part of the spark plug(cue the TWSS jokes). I just pulled it up with no resistance whatsoever. So that's the physical failure. Cleared the codes, installed coil. The code didn't return and the car ran better for the short few days it had coil 1 or 2. I eventually took out the Ruthe-plugs and put in an old set of IK16TTs and startup immediately because shorter with those plugs from 2019.
I installed a bastard junkyard coil(the screw holes don't line up) from a Yaris onto number 4 temporarily and whatever misfiring that remained was cured. That left me to finally isolate the probable failed brake hose that was causing me grief at the same time the engine tossed the misfire code. The engine doesn't run like it's lost all power, struggling mightily to even go up a hill.

The black burned insulator is above the socket metal area.

had very little discoloration(not none) at the ceramic bottom. 3 and 4 had considerably more. And the time elapsed was short, as they were installed last October or November.

This pic is of #3.
View attachment 229050

Coils: Do you think all this possibly had to do with your coils simply not making proper contact with your spark plug vs the spark plug its self?
So i have a 2 stroke outboard boat and having new plugs and new wires that are solid positive click in resistance when hooking them up makes a world of difference.

Densco: IK16TT "shorter with those plugs" Like dimensionally shorter than the Rutheniums?
Startup immediately: When you said after putting in old Densco plugs started up immediately? Like did it not start up clean with the Rutheniums or something?
Burning Plug: Maybe someone else can chime in but that seems to be from the old coils that are easy to pull out and not making as good of contact possibly causing this...?

Does this make sense or am I missing the timetable of the order everything happened with your different coils and plugs?

Maybe just bite the bullet and put in 2 more new coils, regular NGK OEM Iridium plugs, clean the throttle body, mass air flow sensor, check for vacuum leaks, replace your PCV Valve, clean your air and fuel filters.

Anyway, here is why I would do if i had the issues you are describing just to get it sorted.

Ignition:
$200 for 2 new toyota oem coils, (densco i'm guessing)
$70 for 4 new toyota oem plugs ( Iridium NGK I'm guessing)

Air:
$10 Toyota OEM PCV Valve
$20 for a fancy fram XG or whatever air filter at wallmart, I like their deals on the fram and supertech stuff
$20 for a new valve cover gasket
$5 for RV Red seal goop...if you need it when doing the gasket change for that 1 or 2 dots by the timing chain
$15 for CRC Mass air flow cleaner, throttle cleaner,
$10 for upper engine cleaner seafoam stuff to clean your valves

Fuel:
$30 Toyota OEM Fuel FIlter
$15 Lucas Full System Fuel system cleaner

Battery:
Check your Battery and get a new one if you need one
Check your grounds
Pull your battery cables, let it sit,
Clean your battery terminals
Re-attach after a few hours and let the car "relearn" it's new throttle position and what not.

Anyway, you just gave yourself a baby tuneup which is good regardless.

Not sure the Rutheniums are the issues here but maybe someone that knows more than I do can chime in.