2000 mercury mountaineer 4.0

[willisonm]

hey, i have noticed in my 2000 mercury mountaineer 4.0 that it has been idling kind of weird. when it is at idle at any point in time for longer than a couple minutes, it acts as if it wants to die. My father said it could be the fact that it is 12 years old, but i want to know if it anything mechanically i can do. I dont have a check engine light on, and i have had a tune up not but a couple years ago (est. 20,000 miles ago.) and i have a K&N air filter in the stock box. i did clean the throttle body a couple months ago, and it helped a little bit up not much..

so the question is, does anyone have any ideas? i keep reading that it could be that my IAC valve needs clean/replaced..?

thanks ahead!

 

[joe doe]

does it idle funny on cold mornings ?then clear up as the engine warms up?
does it idle funny on every cold start?
could be iac valve but it could also be alot of other things .

could be intake gaskets,upper plenum oring gaskets
fuel pump

to name a few .

more info please

 

[kevinspann]

Is the K&N oiled? It could be over oiled...clean the MAF as well.

As stated, the lower intake gaskets like to fail, causing a vacuum leak that could lead to it dying. Are there any stored codes?

 

[willisonm]

it just acts as if it wants to die. it doesnt tho. fuel pump has been replaced along with the fuel filter. the air filter was pre-oiled when i got it and i havent had to clean it yet. and i really dont want to think that it is a lower intake (or even upper). I hate replacing them. i did on my chevy 1500 just a couple months ago. hate to say it is the worst thing in the world to do. i think it is just something with the MAF or IAC. i will have to clean them and see whats going on there. i may have a exhaust leak starting too. but i have no codes yet so i wont worry to bad now.

Thanks guys!

 

[willisonm]

well i took my car in to a local mechanic and he said that my 3rd gasket on my intake was halfway gone. he replaced them all and i see and feel a big difference in my cars performance. but i am still experiencing weird idles. its like when its in park and i dont have anything on, the RPM lowers really low, and it shakes then a second later, picks back up to close to 1000 then does it again. so im thinking i may have to relearn the idle of my car (in the owners manual it states that when the battery has been taken out or replaced, the car must learn its idle over) so i may try that before i go and replace my IAC or sparks plugs. but i think its almost due for a tune up anyways.

Thanks everyone!
great help!