HI, 1995 civic lx d15b7 4430000 miles 5spd
The FITV that lives under the throttle body,. When the engine is at running temp, is the FITV supposed to be closed and have no vacuum at its port in the throttle body? If not, I think that may explain my hanging idle
When I cover the IAC port in the throttle body, the engine wants to die and I feel a very strong vacuum, When I cover the FITV port (hot engine) Im feeling a slight vacuum, no change in rpm and if I hold my finger over the port long enough, it makes a POP noise when I take my finger off the hole. I dont think its supposed to have vacuum when hot but want to make sure
Thanks
Steve

 

I've never got to test a brand new FITV. They have been discontinued for a very long time now. But I've ripped them open many times and by design I do not believe it can every "fully" seal off the vacuum. As such all my cars have idled and worked well and I've always had a slight suction on the FITV hole exactly as you've described.

My problems have almost always been a faulty IACV. Once car it took 4 used IACV's before one would work and have a stable idle. If you have idle hand, mostly likely I would think your IACV is sticking. Possibly a good cleaning may do the trick even though I've not had luck like many have with that.

 

If the idle speed doesn't change/drop when you cover the FITV port with your finger... then the amount of flow/leak through the FITV circuit isn't affecting anything... and thus, is inconsequential. From memory, I believe TomCat39 is correct and there is always some amount of air bypass afforded by the FITV and it never really "seals off" completely.

 

well the FITV has a bit of vacuum at the port, but it idles where I want it, so Im happy
Thanks for the information

 

Great video on FITV. Adjustment. Fixed mine the other day with this video

 

awesome video
Thank you