starting yesterday my car sometimes begins to idle irradictly after a long drive. as soon as i get ready to park and my car is in the P position when im about to get out... the idle jumps up and down. my idle fluctuates up and down.. i herd it could be cuz of a vaccum leak. or possibly speed sensor? has anyone else expierenced this? how would i go about fixing this problem.??? thanks.

 

fast idle thermo valve ... search it, and you'll find what you need.

 

does anyone kno what steps to take to fix this??? and what vaccum tubes am i looking for if they're disconnected? it only does the fast idle sometimes..

 

dudes?!?! how do u even kno what the problem is?? vacuum lines? FITV? how do i replace that component. how much does it cost? how do you kno what u gotta find and replace.???

 

I had this same problem when I got my (used) '02 Si.. turned out was a damaged Idler Air Control Valve (IACV), and the PCV was also damaged/dislodged. I got a CEL when this happened too.

 

i dont get a cel, the reason im in a hurry is that, i just swapped my motor. so if its a damaged IACV i can just go back to the shop and replace it with my other IACV while the engine is still there. thats why i would like to kno how you can tell wheather its ur IACV or vacuum tubes. or something else...

 

Only way I found out was the dealer checked the code from the CEL, plus visual inspection, and diagnosis came back to broke IACV, and broke PCV. You can easily see the IACV from the front of the engine bay, and looks like would be a quick fix.
but then again, this diagnosis was confirmed from the CEL error code... maybe best to get a specialist to take a look.

 

my 99 v6 aaord was doing this and i had all the same suggestions given too me....turned out too be the butterfly in the throttle body was sticking....gave it a throttlebody clean and reset the pooter..all was good.
if youre new engine has sat for a while i bet this IS the problem,mine did it after sitting in the shed for 2 months.