So i have a 91 XJ and recently it has developed smoke from the vents and is giving the typical bad heater core smell. Ive looked around different sites and from what im seeing its a rather complicated process to replace. I also found something about the pre 96 models are much simpler. Ive never had to do this before so if anybody has any tips or pics or anything it would be greatly appreciated. Thanks

 

if i were you i would have it looked at by a mechanic. its a big job to do. i just had mine done on my 89 and it cost me $440. it turns out the valve that controls the actual heat/ac went bad because of the setup. the valve is hooked up to a vacuum line and that line causes the problem. for your jeep i would check with someone. mine didn't start smoking, it just didn't work. but its still an expensive fix. im just warning you.

 

I have the time and mechanical ability to do it myself. I also just noticed today that it is dripping so its only a matter of time till it goes all together. I just really dont want to tear half the dash apart

 

i forgot to mention the heat still works fine, it just smokes, some times a little, some times a lot

 

i would get on that pretty soon then if you can do it yourself. i know you have to disconnect some coolant and ac lines and that may not go so well. my ac lines had to be cut off. as far as the whole process im not too sure. i know about the dash under the glove box and possibly the center console being taken out. its a day long job tho. and don't go too long breathin in all that smoke, it cant be good.

 

no worries about the ac, removed that a few months ago

 

thats good then. i gotta do an overhaul on mine this weekend. im gettin about 4 mpg and its sluggish up hills and after about 40mph. its due for an oil change and tune up. have you had any problems like that?

 

im not getting the fuel millage i would like to get, around 15 and its a 5 speed. mines a turd on hills if i dont get a large amount of speed built up before

 

best dash removal instructions ive foundhttps://www.cherokeeforum.com/f51/dash-removal-35444/

 

this weekend im gonna see if theres anything i can do. we're supposed to get around 15 city and 18 highway. im just not gettin anywhere near that. bein only in high school with no job sucks too. summer savings for a lift is goin right to gas.

 

i gained a few mpgs doing the 703 injector upgrade

 

Thanks for the link, everything ive been finding is for the 97 on up. Looks like i have a project for this weekend

 

i know my dad replaced the injectors in my jeep years ago but im not sure what kind he put in. i might go through them again and do a good cleaning. what kind of upgrade is that?

 

there called the 703 injectors, i did the swap a while back on mine. It starts easier and faster, throttle response went way up (which is great on the 5 speed) it idles nicer, fuel millage didnt really change for me and the power is about the same, just drives nicer

 

thanks, ill look it up some time. its got 232,000 miles on it so its probably due for injectors or a cleaning again.