After 3 agonizing years of dealing with a poor running JDM B18C5 motor in my civic I opted to finally take the time to figure out why it was misfiring and not idling properly.

Turns out that despite the intake manifold bolts and nuts being tight that there was a microscopic leak at the gasket and lettting in too much air into the combustion chamber. It looked like the previous owner did not use a factory honda gasket and it looked like they tried to jimmy seal the perimeter of the intake ports.

To make a long story short my car no longer idles all weird when it gets hot out, doesn't use nearly as much fuel and I can reliably run my a/c without the engine struggling to stay running

The only issue I have left is my car still has slight bouncing idle when the air is cool out and despite me setting the base idle speed using the factory service manual procedures I can't seem to see where the FITV valve is on this engine.

It is a JDM B18C type R motor so I'm not sure how that particular motor's intake manifold is different that the USDM equivalent.

I think that the bouncing idle as well as higher than normal base idle speed with IAC plugged in b/c the FITV wax ring is likely loose.

Can someone here guide me in the right direction as to where this FITV is located? It isn't obvious like my D series motors or my B18A1 motor where I can literally see the FITV valve on the manifold.

I would take more time to look but b/c I work so late all the time that its dark out when I get home and I'm too tired to keep screwing around with my motor.

Your suggestions are greatly appreciated.

Thanks

 

We don't have a FITV.

 

A shot in the dark...have you reset the computer?

 

yes I reset the computer. Numerous times.

So why would my idle bounce a little when its cold out?

Coolant is completely purged and fuller than full...

Otherwise runs like a charm now.

 

Take the IACV out and clean it up real good. If that improved the problem, time to replace it. Next in line would the TPS. Good luck. Oh, check for any vac leak.

 

gotcha, I'll check/clean the IAC when I have a day off next week.

Thanks