Changed them out yesterday for NGK V-Power Copper.
Not sure how long they’ve been in the Jeep. 99k miles on the clock. Two were out of spec (.04, .042). They look pretty decent to me but, as I said, I don’t know how long they were in. Also, that plug boot closest to the front of the engine wedged between the AC Compressor and engine, underneath the three hoses, was my nightmare.

 

Worn out. See how the center electrode is curved and not flat? Yes, you coulda re-gapped them and put em back in. Not generally done.
You should also replace wires, cap and rotor at the same time. cap with brass, not aluminum contacts.

Clean the throttle body and snug up intake manifold bolts.

 

There is nothing wrong with those plugs. No oil fouling and none look wet. They look great for possible 100K You need a huge overgap to make any real firing issues. I run an 01 with a coil rail eliminator, different from your year but my coil pack is a "screaming demon" very high voltage. The jeep lites off on the first 1/2 second. They also make a coil that fits your 90. Just confirm with them if your connector has round pins or flat pins

 

Yay
Nay

 

@roninofako would you care to elaborate on the nay? I assume you are saying that what the person wrote is not a good idea. I have no desire to change anything from stock unless necessary so I’m happy to get new wires and distributor cap, etc, but I’m not doing any mods.

Although, I can tell you that my MSD coil on my 1993 integra added 500hp at the wheels.

 

The stock ignition is plenty strong, there's no need for higher voltage coils or fancy ignition upgrades. The above statement of nothing wrong with those plugs is misleading...they're worn...due to GASP normal usage. You did the right thing putting new NGK's coppers in...these motors like the old school cooler plugs. Again, no need for Titanium Triple Power Multi Point Lightning plugs, haha

 

When i said nothing wrong...i meant nothing wrong except worn out. They are not running rich or lean and they appear to be not burning oil. I would change them but not alter anything else as your air/ fuel system seems to be correct. You loose nothing by running a hotter spark. I have run several jeeps for almost 500k between them...yes the stock ign is adequate I like my hotter spark...you dont like it...thats your choice

 

@roninofako @blueJeep01 I interpreted the response as it was meant, “there is nothing on these plugs that indiciaria an issue with your vehicle.” Does anyone actually go through the hassle of removing plugs just to put them back in?

 

I thought the comment was about the plugs themselves.

 

What you do lose is $$$ from your wallet, though. Why pay extra money over the life of your vehicle for no gain other than liking running a hotter spark, when it's completely unnecessary.

Not all "upgrades" are upgrades, lol