My turbo H22A Civic was fine until suddenly it just started dying or idling very low (less than 400 rpms) only when I come to a stop. While I am driving it runs great without any hiccups - only when I stop (ie. a stop light, etc.) it does this or if I just hit the clutch in it wants to die on me.

Any ideas what can cause this? AF ratio and Vaccum readings are all great and more or less the same they were last summer btw and the bov is correctly adjusted so it does not affect the idle...

 

Could be an issue with IAC valve.

 

Loose timing belt possibly?

 

if you have hondata try inverting your purge valve.

 

Check your throttle body adjustment. The TB should regulate your idle 100-150 rpms below target warm idle, and the IACV is there to take up the slack. if the throttle blades are shut too far then it creates a dip in RPMs on engine decel because the IACV doesn't have enough time to position.

I see this a lot on B16 with 68mm+ throttle bodies, which is a lot of TB for a small engine and can oftentimes be very difficult to adjust. It also happens to the bigger motors, usually when the throttle stop falls out.

 

Hey you might be right because I do have a bigger TB and never really adjusted it - I will mess with it this weekend probably - been very busy recently!

 

wow makes sense i was still getting this with my iacv cranked way up with my 70mm tb

ill give this a try

 

Yeah you wanna try to be around 750rpms at warm idle

 

Glad I could help more than one person.

 

i am having exact same problem with my setup and right now it running completely stock B16A2.
the only problem is that my car idles fine but only when i press in the clutch after a hard run it will die. it idles at around 750 but the RPM dips to 400 when its warmed up and sometimes will stall out.

 

The problem is a low RPM dip before the IACV can catch it. Adjusting the TB will cure it if, with engine warm, you can free rev the engine and on decel the RPMs dip slightly before resuming target idle speed.

If the engine is cold, due to FIT-V or the engine operating the IACV at a higher duty due to a higher "cold" target idle, it normally won't dip like that even if the TB isn't set right.

 

The symptoms you describe sound like a rich (too much fuel) condition.

 

LOL ok before I get yelled at for bringing my old thread back I thought it would be nice to update on how I fixed this ...

1. The mixture was set just a little bit rich
2. I adjusted the air screw on the TB for a little higher idle and it worked out great - car does not die anymore although it does idle about 150 rpm more which is fine with me.