1) first problem: lately it has gotten to where it doesnt down shift as easily as it used to.. i will be going on a road in overdrive going at 1500-2000 rpms and then if i start to go up a hill it will start to "pop" likes its trying to downshift but something wont let it.. it only does this in overdrive, and if i have it over 2k rpms then its fine.
2) second problem. my fan has always kicked on and off alot, usually it would kick on every 10 seconds or so for a few seconds and then kick off. recently it has gotten to where it just kicks on for a couple seconds then in a couple of seconds it will kick on again.
3) whenever i am parked at a stop sign or light and im in drive and i have the foot brake on there is a vibration that comes from the firewall area, i can get it to stop if i pull up the e brake and let go of the foot brake.

thanks for any help you can give me... its a 99 xj 4x4 at with 140k on it.. i dont think any sensors or anything have ever been replaced on it

 

Sounds like you need a tune-up, cylinders are misfiring giving you a vibration and loss of power. The ac cycling usually means it is low on refridgerant, you can unplug the compressor and the low pressure cut out swith on top of the accumulator to stop this.
Good luck!

 

when you say vibration are you talking about when im at idle or the downshifting problem... and can you give me a lil more details on the fan... i had the ac compresser replaced last summer after the old one went dry and a bearing went out of it

 

and theres no real loss of power that i can tell

 

You can unplug the ac compressor? Mine is starting to make that squeking noise that they do right before they crap out and I dont need a/c, just defrost. I thought you had to have the ac compressor working for some reason with the belt and fan. Am i an idiot?

 

no you don't need the ac comp, unplug it and now it is a big oversized idler pully lol.

 

where you guys the last time the mechanic told me it was required to turn the belt
man im glad i have this site for this XJ

Does defrost work without it? Does the fan still turn?

 

The fan cycles on and off with the ac compressor , whether the ac is on or the defrost is on, if the fan is cycling then chances are the ac comp is as well. When you said a "pop" noise before it would downshift I assumed an ignition miss , usually when ignition wires start to break down, they will act up in od under slight load. Sounds weird that your vibe goes away with the park brake though....... not a bad engine mount, trans mount??

 

yes defrost and elec fan still operate

 

okay on the brake thing i was thinking it could be a brake line or something vibrating... and one more thing... last fall it had a miss and i put in a 02 sensor and it fixed it.. a month ago it starting the same type of miss again, but it has went away for the last couple weeks? so i guess i should throw some spark plug wires in it then?

 

and in order to get it to downshift i have to pretty much put the pedal on the floor.

 

Adjust your kick down cable.

 

https://www.cherokeeforum.com/f2/free-quick-fix-41821/
Here is the link.

 

just did that and it seemed to help alot.. still got a little miss to it so i guess i will still put plug wires on it...