adiga

i have xj 1990 i want to buy spark plugs

i found champion 344 RC9YC copper plus what do you all about this ??

and if the champions good do they have IRIDIUM ? anyone can help ??

Firestorm500

Some people swear by the copper Champions. I have not had good luck with Champions.

I like NGK iridium better.

Your choice.

adiga

can you give me the part number ??

Bustedback

Sure, you want him to install them for ya too?

CCKen

What's wrong with asking for a part number?

Firestorm500

Sorry, I don't have it right in front of me. I got them from O'Reilly's 4 years ago. Any of them should be able to fix you up.

CCKen

Generally Iridium spark plugs are recommended for use in waste spark ignition systems, like the '00/'01 4,0.


Here's a spark plug application chart. These are all copper/double copper plugs.


For the '90 4.0 you may want to try the NGK FR5 plugs. Note the Champion heat range of "9". You want to stay in that heat range for the '90 4.0


Edit: I'm sorry if I offend, but I think using Iridium plugs in a non-waste spark engine is like putting lipstick on a pig.

XJwonders

lmao. None taken

XJwonders

Thanks for the chart. I saved it. And ignore the picture. My phone was on the fritz

Bustedback

It's been a long week of dealing with lazy people with a huge sense of entitlement at work and in my own home. I may have gotten up on the wrong side of the bed this morning.

Jeep Driver

Autolite

CCKen

^ is this a question? If it is, the answer is no.

Firestorm500

Oh, hella no.

That's a FRAM brand.

Firestorm500

NGK Iridium FTW!

100K + service interval. No spark gap changes over time.

Overkill. What's not to like?

mschi772

Use the Champion coppers gapped to 0.035" especially if your ignition system is original. I have an MSD coil, Magnecore wires and upgraded battery cables, so I'm using Autolite iridium plugs gapped to 0.050". This works for me only because of all the other upgrades. My choice to use iridium was solely to see if the small electrode would further enhance flame kernel generation in combination with the increased gap. The bottom line is that they're working perfectly, but I'll probably go back to copper if I ever need plugs again--the small iridium electrode hasn't made a significant impact, and copper is a better conductor.

With a stock system, cap and rotor with brass contacts, Champion coppers, and Belden wires from NAPA are my choice and recommendation.