my idle bounxes really badly when i cold start my 4th gen h23. But when the car warms up it goes away any quick suggestions?? thank you

 

manifold pressure .........

check o2..........

 

im thinking it might be something with my fitv cause it only happens when car is warming up like maybe air in the cooling system or something i had this happen before and i cleaned my iacv and it was fine.

 

does it also do it when u come to a stop??? cuz i know most preludes happen to idle a lot...

 

does it until car is operating tempature and while the car is idleing.

 

check o2 sensor

 

if it was o2 sensor wouldnt i have a check engine light for it?

 

Mine did the same thing and i just figured out what it was. There is a white disk in the fitv, you have to take the small cover off of it and screw the white disk in. Im sure people have posted pics of this, but that is probably your problem.

 

Had the same problem, no CEL, changed O2 sensor, all fixed.

 

i changed my o2 like 3 months ago..

i did just look again and found a hole in my v2 could this be the reason for rough idle??

 

throwing any codes?

iac, ect, or map ?

and i dont know how a bad O2 can cause bad idle. i have a bad O2 and my car idles fine.

 

Do what syntax420 said first. You can do this with the car running and see if this is your problem. When you push the thimble in the middle down your idle should increase. If that outer white ring is loose, your idle will be unsteady when the engine is cold and the thimble is in the down position. If this is not the problem I would make sure that the idle is properly set by disconnecting the IAC valve pigtail and setting the idle to 500 to 600 RPM then reconnect the pigtail and clear your engine codes. The IAC valve is meant to control idle speed by increasing air mixture and will cause the idle to hunt if the idle screw is out too far. Base idle MUST be correct before you can troubleshoot further.

 

no codes i was throwing knock sensor but never messed with idle at this point my mind is leaning towards my fitv.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by amckee &raquo;</TD></TR><TR><TD CLASS="quote">Do what syntax420 said first. You can do this with the car running and see if this is your problem. When you push the thimble in the middle down your idle should increase. If that outer white ring is loose, your idle will be unsteady when the engine is cold and the thimble is in the down position. If this is not the problem I would make sure that the idle is properly set by disconnecting the IAC valve pigtail and setting the idle to 500 to 600 RPM then reconnect the pigtail and clear your engine codes. The IAC valve is meant to control idle speed by increasing air mixture and will cause the idle to hunt if the idle screw is out too far. Base idle MUST be correct before you can troubleshoot further. </TD></TR></TABLE>


im way to car illiterate still to do all that this might have to be done by a shop

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xxredpreludesixx &raquo;</TD></TR><TR><TD CLASS="quote">
i did just look again and found a hole in my v2 could this be the reason for rough idle??</TD></TR></TABLE>

Absolutely not because the intake is before the throttle body. I think the air filter is a bigger hole than the little one on your intake tube.

 

woot problem solved thanx for the help guys

 

what was the cause?

 

the little thimble in the fitv was all the way unscrewed for some reason . but i had another valve off my old h23 swapped over runs l ike a champ

 

You could have just screwed the thimble back in, but ohh well, glad to hear you fixed it!

 

lol yea i know but i wanna get experience in working on my car so i did all the work lol

 

wel now you know, and knowings half the battle

G.I. Joe!

 

very true and im getting good at working on it