Idle climbs to 3000rpm in park?

[hellbound76]

Hey guys, I have a 98 explorer XLT 4.0 SOHC and I just recently changed the crankshaft sensor. And now, immediately after start, the idle climbs up to 3000rpm's at a steady pace and stays there till I shut off or shift into D. I get to the point to where right after start I throw it into D so the rpm's don't get up there. While in D with brake applied stopped at a light it then idles at 1200 rpms and acts like I am holding it back from a fight in a schoolyard. Than after driving awhile, sometimes it goes back to original working condition then gets an additude again. It seems to be an off and on occurance, and I never know when it will happen. So my questions is, with the new crankshaft sensor that is not adjustable, should I get the PCM reprogrammed to acknowledge the new part? Seems how the problem started after the part replacement.

Thanks everyone in advance for your response.

 

[bluesman2333]

Unplug the IAC to see if the problem goes away. If it does, then the IAC is at fault. If it doesn't, then a vacuum leak is at fault. At least that is what I suspect.

 

[Tbars4]

...x2 on the vacuum leak...check for breaks and disconections all around the area you were working...

 

[BrooklynBay]

Welcome to this forum! I agree that it might be either the IAC or a vacuum leak.

 

[hellbound76]

Thanks!!!

Thanx, I will try the IAC this weekend and hope to god that's it!!! If its not one thing its another. HEEHEEHEE Now I am delirious.

Again thanks,

Just a girl tryin to keep her explorer alive.

 

[Tbars4]

...checking the vacuum hoses is cheap and quick...

 

[hellbound76]

Your right tbars4 I will try that first. then I will do the iac test and replace if necessary. I like this forum thing. Many a days I spend pondering problems of my explorer. I like that people on here know what they are talking about. Truely Awesome.

ThaNX AGAIN. I will write more if I have more issues or can help anyone.

 

[96XLTRanger]

spray brake cleaner around your engine, without a light near it or a cig in your mouth LOL if you notice any change in idle, isolate the area, then inspect it more. you'll find the general area. I hear water works but i wouldn't do that cuz my engine bay is rusty enough.