Okay so for the last week or so when id go to start up my 99 xj for the first time in the morning it would idle rough and stink a little bit. This would go away after driving for a minute. Today i left it idling like that for a minute too long i guess and when i started going down the road i felt a quick loss of power but it came right back and drove normally after a minute and my check engine light came on. I drove straight to auto zone and had them check my code and it came up with cylinder 2 misfire so i put new spark plugs in. When i went to drive the xj again after sitting for an hour i got the same hesitation while just starting to drive but it only does it once and drives normal after taht.

What could it be?

 

Too long/didnt read version- bad idle/slight hesitation at first take off of the day for a few seconds, runs fine until it sits again. Check engine light code says cylinder 2 misfire

 

For single cylinder misfires, you must concentrate on everything related to that cylinder:

1. Spark plug (you replaced that; don't use Bosch plugs, be SURE all plugs are gapped to .035)

2. Spark plug wires: Replace them!

3. Distributor cap: Replace it and the rotor when you're at it

4. Fuel injector: Swap cylinder 2 injector to a different cylinder and see if the misfire follows. If it does, you know what injector is bad

5. Internal condition of the cylinder: Perform a compression test on all cylinders (dry/wet) and then see where cylinder 2 falls. Should be 120-150, with no more than a 30 psi variation between cylinders

 

x2 start with what tj walker says

 

Lol my battery terminals were all corroded any my jeep wasnt even starting so i cleaned em up good. I think the misfire and ****ty idles were because of the bad connection haha... Whatevs

 

Also, i ****ing hate electronics and wish this thing had a kickstart like a dirtbike... Man would that thing be hard to kick! Lol

 

Why shouldnt i use Bosch plugs?! I have a random miss in cyl 1 & 2 (by random i mean it truely is random. it only happens every now and then, and no hesitation in power)

 

Bosch plugs have been found to be the cause of missing with some (certainly not all) Jeep 4.0 engines. The mechanism that causes it is not yet determined.

Because it is a possibility, I won't install Bosch plugs or recommend them. And I really am a pretty big fan of Bosch products generally speaking.

84-99: Champion copper plugs
00-01: NGK V-power (champion will work okay, but the NGK gap holds up longer with the distributorless, coil pack type of ignition found on the 00-01)

 

wait, wait...I have Bosh wires..im not sure what kinda pugs i have.

Is there still a problem with that?

 

Bosch platinum plugs have been linked to misfires in systems where the plugs fire every revolution. My old ford ran fine for 5k miles on platinums and then I searched for 15k miles for the cause of the misfire. Swapped plugs to champion copper and problem gone.

Most things from bosch are good including the pay, but I stay away from the plugs on modern engines.

 

What about Champion Platinum plugs? Is platinum an issue, or solely with the bosch? I just replaced all my plugs and got an OBD tester. Cylinder #2 misfire. Not sure if it was present before or not...