Newer LJ owner (2005). Just going through some routine maintenance since I have no prior records. Decided to change the spark plugs. After doing some research I ordered a set of Autolite XP985 Iridium XP plugs.
First off, I'm normally an NGK guy on most of my other cars (Import/German). I would have to say I was a bit disappointed with the Autolite. The gapping were way off, some of the plugs were almost touching the ground. Had to regap .030-.035 not a bit deal. I ordered 12 plugs since 4 comes in a box and I figured I could have another set for the future. The ground, in addition to being off from a gapping standpoint, many of the stems were all over the place, slopes of the stem varied and some were misaligned and not exactly over the electrode. Anyways to my question.
The plugs in the jeep were NGK ZFR5N Copper plugs. The interesting thing, all the plugs were more than .060 gapped. This was the most my tool went to, it might be something like .065 or 0.70 as it was close. Could this just be wear, or was there a reason for this type of gapping? I ask, because after installing the new iridium plugs and driving the jeep, it definitely is less punchy off the line (first gear), where the throttle petal is normally very touchy, it was dulled down a bit.
In my research, I read some other folks noticing the gapping was within this range too, one thread mentioned it was the first spark plug change, so from the factory gapping could have been larger? Or do the copper plugs really wear that much over time? I've got 80K miles, so maybe these are the original plugs as well?
Thinking of switching back to the copper NGK plugs, should I gap recommended or go larger? Jeep ran fine with the old plugs with .060 gapping.
I also read an aftermarket ignition could allow for wider gapped plugs, how do I tell if I have one? The strip of coils looked to be OEM, not sure what else to look at to determine if something has been upgraded.
Any help would be great, especially the pro or cons of running the wider gap with the copper plugs.
Thanks!!
First off, I'm normally an NGK guy on most of my other cars (Import/German). I would have to say I was a bit disappointed with the Autolite. The gapping were way off, some of the plugs were almost touching the ground. Had to regap .030-.035 not a bit deal. I ordered 12 plugs since 4 comes in a box and I figured I could have another set for the future. The ground, in addition to being off from a gapping standpoint, many of the stems were all over the place, slopes of the stem varied and some were misaligned and not exactly over the electrode. Anyways to my question.
The plugs in the jeep were NGK ZFR5N Copper plugs. The interesting thing, all the plugs were more than .060 gapped. This was the most my tool went to, it might be something like .065 or 0.70 as it was close. Could this just be wear, or was there a reason for this type of gapping? I ask, because after installing the new iridium plugs and driving the jeep, it definitely is less punchy off the line (first gear), where the throttle petal is normally very touchy, it was dulled down a bit.
In my research, I read some other folks noticing the gapping was within this range too, one thread mentioned it was the first spark plug change, so from the factory gapping could have been larger? Or do the copper plugs really wear that much over time? I've got 80K miles, so maybe these are the original plugs as well?
Thinking of switching back to the copper NGK plugs, should I gap recommended or go larger? Jeep ran fine with the old plugs with .060 gapping.
I also read an aftermarket ignition could allow for wider gapped plugs, how do I tell if I have one? The strip of coils looked to be OEM, not sure what else to look at to determine if something has been upgraded.
Any help would be great, especially the pro or cons of running the wider gap with the copper plugs.
Thanks!!
