low rpm 98 chevy Tracker

[98TrackerMan]

Hi, New here to post- I have a 1998 4wd-4dr 4cyl Tracker- purchased it new- it has about 97,500 on it now- NEVER had a problem-all I ever repalced was a $10.00 temp A/c switch in 2007-tires of course- fan belts-plugs & wires. I started her up the other morn (22degrees out) and it warmed up as ususal, I noticed that the rpm's were dropping a bit below the on dash guage-looks about to below 900 and the engine would stutter and then the rpms would pick up by itself to the normal just below the "1" - when i put it in Drive-rpm's dropped- by stepping on gas they came back up- she's been faithful to me- so not to breakdown on the street- i took my other car- Started Tracker up the next day -same thing but not as bad- I have't cked anything in detail yet -it's been too cold here -but a quick look under the hood- things looked ok- I suspect maybe some type of sensor( or module- or maybe it's time to overall routine maintenance? No new gas-Gas is at 1/2 a tank at regularly used station i'v been using all week- It's ALWAYS run smooth- just like when I first got it-It's my daily driver-cheez I also read that I should've replaced the timing belt a while ago-but it was running so good - time flies! appreciate suggestions-miss my "T" ride!- reading some of the posts it looks like a TPS? Thanks a bunch This is Super Duper info here.

[jtgh]

1.6L is belt and 1.8L is chain
so 100k on a belt is ,well asking for valve hitting the pistons.
you engine is NOT freewheeling. and the belt will NOT last forever.
its the one thing never to skip on all 16valve engines.

your ISC is sticking, pop it off and flood it what carb cleaner and shake it like dog with bone.
i fill mine with this fluid,and then tickle it with a split Popsicle stick (wood)
push it back then forth.
see video of one under test here. (using external battery or power supply)

mine.
http://carfix.stufftoread.com/sensor...deos/IAC-E.wmv

1 min load wmv video
see it , hear it.

yours looks diff, but works just the same way.
it is an air valve solenoid.
next to Throttle body, see it? It controls idle.
look here.
http://carfix.stufftoread.com/sensor...6L-plumb1w.jpg

part 60 Isc or IAC same-o

many cars do this ,cold.
it is easy to clean, just leave hose attached for green slimeleaks out

[98TrackerMan]

Excellent- I hope to be doing this ASAP- and pick up a good belt kit -- should be getting outside workable weather this week
Will keep you all updated on progress and maybe I'll take some pics too!
THANKS!!