I have a 89 Jeep Cherokee Limited, and it has idling problems, it also smells like gas out of the exhaust. I am mechinically challenged and dont know much about cars. The Map sensor was tested along with the tps sensor and they turned out fine, the o2 sensor was the only thing that was wrong, and it was replaced. Im idling at 100 rpms at most times, sometimes if im lucky, 200 rpms. The caps and routers along with spark plugs etc were also changed recently along with a oil change. My cousin had placed a new idle air control valve in my Jeep that was for his Jeep and it did nothing. Im totally clueless on what could be wrong, being that im not smart when it comes to mechanics and cars.
Thanks for taking time to read this.

You said you replaced the plugs, etc. Did you also replace the plug wires? How about the air filter? You could also clean the air intake.

Idling at 100 rpm is very low. Did the problem start suddenly or has it been getting gradually worse?

Its always idled pretty low since ive had it, and i did replaced the wires. The only thing that hasnt be replaced would be the air filter. Im going to get that replaced and see what happens.

Ive had the Jeep since last July and ever since we bought it, it has been idling pretty bad. It runs fine though when im actually driving it.

Ok i cleaned out the air filter box, there was leaves and dirt on the bottom of the air box and it was underneath the air filter, i sprayed that stuff outta there. Its running better than it was before, but im going to get a new air filter when i get to town later today. Thanks

Welcome. You may want to check the throttle body also, if the air filter/box were that bad, it's likely you have some buildup in there also...every bit helps.

Ok is the throttle body the area where the iac is plugged in? Im not real smart on locations. The Jeep smells like gas, and i dont know what is causing that, could it be the throttle body causing this because it needs cleaned? Or could it be a crank sensor needing to be replaced? Oh and one last thing, the mechanic next door to us hooked up his computer to my Jeep also and found nothing wrong except the exhaust system wasnt doing what it was supposed to, he said it has a exhaust leak, could this also possibly be a problem for its bad idling?

Throttle body....go from the air filter box, there's a flexible tube running from there to the engine. If you disconnect it where it joins the engine (mine has a clamp) you'll expose the throttle body, a round metal opening for the air to get in. There might be some carbon deposits inside...a good cleaner will get that out, make sure to get the stuff that won't harm your sensors.

Bad idling could also be caused by a vacuum leak, so inspect all the vacuum hoses under the hood.

The exhaust leak might contribute to a bad idle, so having that repaired isn't a bad idea.

Still smelling like gas....is there a leak somewhere? Does it smell like gas at the exhaust, in the engine compartment, or both? What kind of mpg are you getting?

Well now that i remember about the throttle body, we have cleaned that already, just a while back. As for the vacuum leak, im hearing a hissing noise coming from this hose that leads from the fuel injectors to the top of the engine, it is a little yellow piece that is close to my map sensor, the hissing noise is coming from there, and as for the exhaust leak, it smells like gas from both the engine area and muffler area.

I'm not familiar with the hose you're talking about, but if it's hissing you'll want to inspect/replace.

Gas smell from the exhaust is an indication of a rich mixture...you may need an O2 (oxygen) sensor. You might want to go to an auto parts store and see if you are getting any computer codes - they (major chains) usually have diagnostic stuff they will hook up for free.

The o2 sensor was the thing that was wrong when we tested the sensors, we have sense then replaced it, and i already tried with the auto stores, they told me that they could only hook up the computers if my check engine light is on.

So...loosen the gas cap a bunch, so that the check engine light comes on!