Hi first post here. So I bought a 2002 Montero limited. I had it in to the shop for a tune up. Got wires, plugs, temp gauge fixed, vacuum line fixed for front differential, they cleaned the throttle body as well. So I'm having a lag time of a couple seconds when I give it gas from a dead stop. I can floor the pedal and nothing till it gets over 1k or so. The car idles at almost 1k when in park but drops to 500 rpm in gear. I replaced the coil packs myself. I'm thinking it might have to do with the idle control sensor but not sure. No codes are showing either. And ideas would be helpful.

 

How many miles does your sport have? Some ideas for the sluggish acceleration are, clogged air filter, faulty O2 sensors (not triggering a code yet but is still messing with Fuel/Air ratio), loose throttle cable, faulty fuel pump, clogged fuel filter, transmission stuck/starting out in 3rd gear. As for the low idle issue, this could be the idle air control valve as you mentioned or some of the aforementioned items. Do you have any issues stalling at red lights?

 

It has 175k on it, no stalling at red lights. It has stalled once or twice before warming up. I'm planning on getting another idle control sensor/valve for sure. I can confirm the air filter is good. I do get a bit of rattling underneath but the muffler shop said it was a loose heat shield and the exhaust was good. I wonder if maybe the cat might be clogged.
And I'm able to run it through all the gears so I'm pretty sure the trans is ok.

 

If you have an infrared thermometer, you can aim it at either end of the catalytic converter to check for either a failed cat or a clogged cat. When the vehicle is warmed up to operating temperature, have someone rev the engine to about 2500 RPM, wait a few seconds and aim that thermometer at the output pipe of the cat(get as close as you can for a more accurate reading). Normal/average readings should be around 500f/260c. If the input is significantly hotter than the output you may have a clogged cat or if the output is about the same as the input or colder, you likely have a dead catalytic converter.

Also check for failing fuel pump or clogged fuel filter. If the filter hasn't been changed, I'd just change it now because at that mileage it needs to be changed anyways and they are dirt cheap.

 

Awesome, will do, I appreciate the help!!

 

New issue. The hits keep coming. Now the battery is dieing. New battery and terminal. So thinking it's the alternator, or some draw on the battery I'm not aware of. Errrrr frustrating to say the key

 

Yeah, I guess I didn't think of that one. If the alternator isn't putting out what it should, it definitely could cause the vehicle to act sluggish.

 

Well replaced the radio on the 4th was running not great but the way it was. Then decide to turn on the AC and it choked and died. Won't idle any more. Beyond disappointed. Don't know what to do now.

 

Did you get the alternator tested? Have you tried replacing the MAF sensor with another one? You can pick them from salvage yards for like $10. When I worked at a parts counter, the computer said you can even find them on Kia Sorentos up till 2003.