Hers's the situation... On start-up, immediate jump and hold at 2000 RPM. At operating temperature, settles at 1500. I start driving and I get a jerking deceleration. This happens any time I let off the gas at 3000ish and above. Or just after a cold start in the morning. Also get bogging/stuttering and backfire on acceleration below 3000. I have a 1995 Civic EX - D16Z6. Now, here's what I've done so far...



Cleaned IACV at least five times. (Even applied 12v and it works)
Cleaned throttle body.
Checked for vacuum leaks like five to ten times. (Carb cleaner and propane)
Tried to do an idle relearn twice.



Nothing has worked at all yet. I have completely run out of ideas. And I have a constant headache because of it. And it's embarrassing. So if anybody has any ideas for me, I would really really really REALLYYYYYY appreciate it!

 

I cleaned the FITV as best I could... Snapped a couple bolt heads in the process... No improvement in idle... I think I'm gonna just buy a Skunk2 TB, which doesn't even have an FITV port, then just block off the IACV on the manifold. I've been trying to read up on other people's experiences with an IACV/FITV delete, but there aren't a whole lot of people who have done it. And most who do don't live up in North Dakota with the extreme winter and therefore don't necessarily need the two valves for cold starts. So my question now is, can I do the IACV/FITV delete and just hold a touch of open throttle during cold starts to heat the engine faster?

 

When you start it, does it do a weird revving thing? Like you start it and it goes to 2 but then it fluctuates until it finally settles around 1-1.5? My 1993 Honda civic does it and my dad just says to wait until it idles enough to start driving

 

Yeah, something like that. It goes straight to 2k or so and sometimes stays and then settles to 1500 or so. If it bounces on startup, I just tap on the gas and it stays still. I just don't know how to fix this.

 

I would definitely try to reset the idle, the way it says to do it in the FAQ's and recheck the timing. Mine was doing a weird little surge on start up, not too much but enough to notice and once I reset my idle and timing it went away.

 

When was the last time you did basic ignition maintenance like new spark plugs, cap & rotor, wires?