high idle

My 99 Rodeo has been idling really high, when I first turn it on it's about 2000RPM when I put it into drive it's at about 1250, I'm wondering if this could be the throttle position sensor or something else, anyone have any ideas?
Thanks

could be a couple of things. I a leaking manifold gasket or there is some switch in the power steering pump that when it gets dirty it sticks open (you can have your power steering pump flushed to see if it helps).

-Ryan

just disconnect the connector at the P/S pump for the switch you dont really need it. It is designed to idle up the engine while turning but its a v-6 so just do away with the switch it will not cause the check engine light to come on

Here is another thing, Everytime I unplug the battery the idle is fine for a few days and then it starts idling high again, any thoughts?

By unplugging the battery you are resetting the ECU. The ECU then relearns and corrects for the leak. And then a couple of days later it poops out.

-ryan

just disconnect the connector at the P/S pump for the switch you dont really need it. It is designed to idle up the engine while turning but its a v-6 so just do away with the switch it will not cause the check engine light to come on

it sound like it's one of the sensors. i think it's either the oxygen sensor (which needed to be changed at every tune up no one told me about that) or the erg or erv (exaust gas value->somehting like that) has to be cleaned. for some strange reason is it's clogged the engine especially fuel injected runs rough if not cleaned

there are 4 O2 sensors on th 98-04 Rodeo's. If one is bad the CEL will be on and there will be a code for which one it is. O2 should last at least 150k or more.

EGR cleaning is easy and only costs a buck or two for the carb cleaner. See my FAQ link below for a how to.

-Ryan

Thank You for all of your help, I'm looking into all of those things, it's hard to figure out when I don't have a check engine light.

first off: qualifications- motorcycle mechanic...so i know just enough to be irritating...secondly a manifold gasket leak would result in either "seeking" idle or a racing idle...USUALLY???!!!...probably is a sensor going or gone bad...the reason why i think is my wife's 98 rodeo just started doing the same thing...high idle to 2-2500 at cold start and SLOWLY idles down...this is not normal...and to piss me off doesn't do all the time but more and more frequently..no CEL but can make go off by unplugging various sensors at intake manifold...by the way to clear CEL open fuse box in engine compartment and pull 15 amp fuse for ecm and then ecm relay to drain brain (both are clearly marked positions on top of box)...suggest in that order to prevent arcing...replace in reverse order...
now here is the question...anybody figure this problem out yet???????...check under honda passport also is same car...have found a few posting of questions but NOOOOO ANSWERS?????

seahags- did you try unplugging the idle-up switch on the power steering pump? That switch may be acting up (common on zu's), epsecially when the ATF in the power steering system is nice and cold. The idle up really isnt even needed with the V6.
G/luck
Joel

keep thinking that a vacuum leak wont cause this if so thats all on you not saying thats whats wrong with yours but its possible aluminum will expand more than steel when it expands it may be sealing the leak or reducing it I have sen it many times

first let's start by saying that a question is sometimes just a question, meaning you don't know something or need more info...and sometimes a discussion is not an argument but an exchange of ideas...so anybody copping an attitude is just looking for an argument...any body can post anything they want to on the internet w/o qualifying themselves...having said all that,my question is why would the steering fluid temp have little, if any, to do with the cold start idle???...first off i live in the deep south so it has not been below 65-70 lately in morning and if it did affect cold idle it would seem to be very minimal...most fuel injection takes into account things like throttle position, intake air temp, engine/coolant temp, barometric pressure and then after startup adjusts mixture-injector opening time with o2 sensors (which may locate one in the egr circuit???)...the one wire approach would indicate a thermostatic normal open/or normal close switch (like harley oil pressure switch- if the oil has pressure, the switch works, the light goes out, you drive away)...
a temp switch may trigger a different map in the brain but maybe only a few rpm, not 1200 usually then shooting up 2-2500???... that is question, if anyone is a master tech or fuel injection specialist please speak and inform me...that's why i'm inclined to believe a bad sensor...( what do you get if you ask 10 mechanics the same question?..." I don't know man, y'all take a look at this, I can't figure it out!!!!")...so again which one could it be w/o a CEL???...
but hey engineers have been known to program in some silly stuff...they never ask a mechanic where it goes, just that you need a special tool to get it out!!!...
just to make me beat my head against the wall harder i just went out and found my steering pump was already unplugged somehow???!!!...ARGHHHH!!!

seahags- another thing to try, is clean your mass air flow sensor. Dirty MAF's sometimes cause idle & perfomance issues with our trucks, without ever setting a code/ lighting the CEL.
G/luck
Joel

ancient mechanics saying- "when all else fails, read the manual!!"""...went and bought the haynes manual at pep boys tonite...you were mostly right about the power steering switch...but i read the words "cold" and thought you meant temp... is actually a pressure switch (did i mention the harley oil pressure switch???...seems my unconcious brain half may know what it is doing!!!)...it does idle to keep the steering from killing the engine when off dead straight...
did also pickup can of throttle body cleaner and tried that trick also...did not really seem to make difference...also changed fuel filter for "s and g"...also no noticable idling difference...it has not idle high at all today but i did have to clear self-induced CEL several times so the ecm may not have relapsed yet...
leaning now towards idle air control switch on top-side of intake or the egr replace/clean trick...DW

seahags- did you try unplugging the idle-up switch on the power steering pump? That switch may be acting up (common on zu's), epsecially when the ATF in the power steering system is nice and cold. The idle up really isnt even needed with the V6.
G/luck
Joel

Yep this solved the High idling problem for me. After searching all over the net this is the answer. Just unplug it. SO we dont really need it right? Other then that the car is fine.