I've researched, thanks in advance for any help.
Car: 2000 Honda civic SI
Full turbo, wire tuck, 400whp, etc.

Having an issue with my idle. Started a month ago, picked my car up from getting re-dynoed. Had issues with cold weather, after being warmed up car ran fine...no issues. Started my car up today, will not hold any kind of an Idle, and completely shuts off. I have to rev the car to keep it alive... Any time the car is at an idle, it shuts off.

Checked so far: all vacuum lines, spark plugs, took off IAC and cleaned the screen etc...still does not fix the problem. In addition the fuel curve for the idle is fine that was set by the tuner, so the car is getting enough fuel at idle.
My question, should I just buy a brand new IAC valve?. Ive heard that these really don't go bad in some of the research that Ive done?

Thanks again for any help

 

is there any CEL? makes no sense in replacing your IACV when you dont really know what the problem is..

 

no cell at all...no check engine light, etc...

 

If the IACV is bad, will it throw a CEL?...Also, my car is 9 years old, so how often do these usually work for?
thanks

 

what program are you running? Are you running a wideband? how do you know the fuel is good?

edit: Also there is a setting for ect vs fuel/idle so if the fuel curve is fine at one temp it may not be good at alot colder temp.

 

using hondata s100...the car was tuned when it was 20 degrees outside...it was 55 today and just kept shutting off...I had the tuner double check for the cold start fuel settings...just trying to see if I am forgetting anything...thanks

 

I would get a wideband even if you aren't doing the tuning for situations like this and for peace of mind.

 

thanks, maybe I will invest in a wideband...still trying to figure this problem out though...if the IACV is bad, it will throw the CEL correct?

thanks

 

most likely it would....but it could be other things..i would check to see if your getting enough fuel...it sounds like when a car has a kill switch..with it off the car would start but get cut off due to the lack of fuel...

 

ok thanks, Ill contact the tuner again....

 

I've been trying to figure this out...I think I might have a bad IAT sensor?...Does anybody have any kind of similar experience as mine?...Weird thing is, there was no code thrown...I've been told that a bad IAT will not always throw a code?...
thanks for any help

 

LMK when you figure out the problem mine did the same thing! I replaced the feul pump, fuel filter, injectors, checks all vacum hose, clean pcv pipe (or whatever it is call), wires, cap, spark plugs) Its running now, but now it lags in low rmps

 

I ordered a new IAT....I'll let you know...I'm going with the cheapest route possible first then from there prob. to a new IACV...
thanks

 

where you order it and how much? i need to get one for my 99 civic si coupe

 

go to majestic honda....and then go to the parts department

its like 40 shipped...why dont you wait till I know what it def. is?...so you dont have to waste money?

 

unplug the IAC and start the car and try to make the car idle with the idle screw on the throttle body and whatever fuel manage you are running, disable the IAC all together, it will idle much better.

 

thanks, I ordered a new IAT a few days ago...Im just waiting for it to arrive....

 

I got the new IAT in the mail, and installed it...It was the culprit to all my idling problem...It was $40 shipped brand new from majestic honda. So, this is a good place to start if you have idle problems like me (described above).

Pimpchickpcfl, I would give this a shot....Let me know how it works out...