B20B idle problem
 

ok just a week or so my car started to idle very high when im stop the rpm would go up and down from 1000 to about 3000 rpms back and forth would any body know what is wrong with it and what i could do to fix it.

i took it to a car shop and he tryed to ajust my idle but that was not the answer he told me that my throttle body was dirty it had to be clean.
but i don't know could you guys help.

could be you have air in the coolant system
or your iacv is stuck ..
or your fast idle valve is stuck

does it only happen when the car is fully warmed up ?

yes it does.

are you using crome to tune your ECU?
if yes thats your problem.

what?!?!?!

Crome doesn't equal idle issues.

Sounds like a vacuum leak, or IACV or FITV problem or air bubble in your coolant (like kickz said).

i've had 3 cars tuned on crome.

the ONLY time i had a similar problem like this, is when my IACV was effed.

but, it's not a cheap place to start buying parts for - unless you can pull one off a friends car and try it out, or find one in a junkyard and pull the part off yourself...

usually when i've had vac line issues, the RPM's stayed high, right from initial ignition.

also, on newer cars. fast idle can be an issue.....

got any friends with honda's you can pull the IACV from? (its easy, 2 bolts, 2 coolant lines, one wire plug)

It's a FITV issue most likely, I'm too lazy to tell you what to do.. if you search on honda-tech or jdmrides theres a nice write-up by wildoutgsr