Im wanting to replace my spark plugs even tho I probably dont need to lol. Was thinking of putting E3s in it since they are suppose to boost performance and mpgs some. Right now I have champion coppers in the jeep. Its the 4.0 renix engine. What plugs would give me the most bang for my my buck. Would going up a heat range help any or would that be a bad idea?

 

NGK coppers and be done with it. How long since it got new wires, cap, and rotor?

 

No gain in going up a heat range if the current ones aren't fouling out. Could do some harm though. If the current plugs are in good shape and working correctly, personally I'd leave them and spend the money elsewhere.

This motor doesn't benefit from fancy plugs, it isn't exactly high-tech. Think "tractor". All they have to do is light the cylinder and keep doing so for a reasonable period of time without fouling or pre-igniting. Standard copper NGK's are as good at that as anything.
Some folks love Champion, others hate them. If they're working correctly, then they are. I'm not sure what additional E3's would accomplish.

 

E3s would accomplish their vendors making some dough.

 

Yeah Just stay with Champion or NGK. Stay away from those high priced gimmick plugs. They are garbage!

 

Definately stick with keeping your Champion plugs fresh. As Cruiser suggested the wires, cap, and rotor wouldn't hurt. You can't run the E3 Plug, the 10,000++ HP gains are just too much for the Renix system to fuel. Definately the best upgrade is keep your existing systems fresh.

 

Yep, what others have said about the space age plugs,,no gains to be had. Stick with the basics and correct temp. range.

 

Couldnt tell ya lol wires look relatively new when I bought the jeep. Cap and rotor no clue I plan on changing them as well. Is there a certain brand I should go with? Also would a msd ignition system be worth looking into since Im building a 4.6 low buck lc engine?

 

No MSD. Napa Premium cap and rotor with brass terminals, and Belden wires.

 

Cool saves me money lol thanks man will be doing this asap maybe itll help my idle out. Right now it idles up and down and chokes like its bout to stall so Im hoping this will be the right place to start. Also wanna run a compression test as well

 

Definitely the place to start.

Recap what you've done so far to address this issue.

 

x2

 

So far Iv only replaced the plugs about 3-4 tire rotations ago so probably 12000 miles ago I did them

 

Any of my "tips" performed and if so, which ones?

 

Will be doing the ground up grades as well as tps adjustment iac cleaning and may move the iac into the tube the that my air filter is going to be attached to since Im putting a cone filter on it soon