4.0 Question--on a ZJ, thus, non-tech

[Cottontail]

I had a mechanic replace the distributor, distributor cap, and rotor on my 96 ZJ. They wanted (get this) $98 to do the plugs and another $68 to do wires, so I decided to do them myself.

Since the work was done, the ZJ idles rougher than it did, but runs out just fine. The tank of fuel that was in it when the work was done got me a 16.something mpg. That is significantly lower, as we are usually in the mid 19.something mpg with city driving. I haven't run down the second tank yet, so I guess it could be a fluke.

It could just be a bad tank of gas or 2 as the last 2 tanks came from the same dealer. But my question is this:

Could I be idling rough if one of the plugs didn't get in properly? There was one that was a little stubborn, but I didn't force it and think that I got it in just fine.

I guess I just want to cover all the bases.

Thanks

 

[Cottontail]

You're kidding me...15 views and no one knows about spark plugs?

Come on someone...throw me a bone!!!!

 

[Kejtar]

You're kidding me...15 views and no one knows about spark plugs?

Come on someone...throw me a bone!!!!

Which plugs did you put in?? I remember reading about people saying that certain plugs on 4.0 didn't seem to work too well (XJ) and they always recomended going with either dealer ones or champions (I think it was champions)

 

[Cottontail]

I used Bosch plugs and wires.

 

[Kejtar]

OK, that's interesting then.... You might want to run a search on OEM and see what you can come up with, cause I remember specifically people complaining that bosch plugs and aftermarket wires and dist+cap have given them grief and as soon as they switched to champions or oem stuff everything cured itself.... On the other hand, I don't have any complaints towards my bosch plugs (I run the 4+)...

 

[EMTJeepers]

I have run Bosch +4 and currently have +2 in, and have had no problems with either in my XJ, wifes TJ, or our CJ7. If it didn't seat properly, you may have cracked it. I would pull the one that was tough and replace it.