I replaced some extremely nasty (I'm guessing factory) spark plugs the yesterday. I did a quick startup and let it sit at idle till it warmed up to regular operating temp 200-210(normally 200).
Today I go to take it out with my son and it has an extremely low idle jumps about 50-200rpms.
I proceed to take the newly purchased spark plugs out to inspect them and check the gap again (gap is .035) on all so good to go. I put them back in, not in the same order and it runs like it should. I drive it around the block and it still sounds good.
I then let it sit for about two hours and take my son who had just woken from his nap(he's 2). I go to start my Jeep and it sounds ok. rpms are idling around 600-800 now. I drive about half a mile and stop at a stop light and the engine just goes back to how it first started off. Low rpms idling around 50-100 now. Light turns green and I press on the gas to head on my way. While driving(cruising or on the gas) it's fine. As I'm slowing down it's fine. As soon as I stop it drops it's rpms
I bought RC12ECC number 438 Champion copper plugs.
I noticed with 2 of the NEWly purchased plugs that two of them had silver tops and not a darkish copper type of look. Went back to exchange them but the other ones at autozone were the silver top as well.(see pic below)
I went to Checkers/O'reileys and bought some new plugs tonight but haven't been able to test those out.
The Jeep was running great before I touched the coil rail and spark plugs. So, Unless I touched something else which I'm positive I haven't I'm guessing I have a bad plug or a bad coil rail or both.
What do you think?
Do I need to replace the spark coil rail at all? If so how many miles?
I am 13 miles off from 60,000 miles on the odometer.
edit :: I also found out that every place I went I could not get Champion truck plugs p/m 4412 ( everyone said they aren't being made anymore and that they don't carry them. I asked pepboys, autozone, checkers/O'reileys, napa.) I was going to try these instead of the RC12ECC.
edit edit :: I torqued everything down to spec as well. 30ftlbs for the sparks and 20ftlbs for the spark coil rail.