I just got my S2k about 2 weeks ago and I am trying to make sure everything is okay. What is the typical idle when the car has been warmed up? I am usually one to two ticks below 1k....

Also is it common for the idle to dip under hard breaking???

Finally...does anyones idle when the car is warmed up go up and down a tick every so often?? Mine seems to do that and I want to make sure everything is okay....

Thanks in advance for your help!

 

Your idle seems normal by your description.
The "dipping" of the idle you speak is also something that has been noted by many owners on this board. It will also happen when you just sit there and rev the engine up and let it fall back down. Some have even indicated that their engines nearly kills or has killed. It is a mystery that so far has had no resolution. It seems that every once in a while the computer has a brain fart and can't decide what to do with all the information it gets from all of its sensors. Most have also indicated that once the ECU has had some time to "learn" the problem goes away. Mine does it about once a year usually at the onset of the hot season and takes a few episodes to clear itself up. I've noticed too that this "stumbling" is associated most of the time (but not always) with the A/C being on.
Again, because the ECU depends on info it gets from all its sensors, a slight fluctuation in rpm is normal.

 

Also, your idle might drop a notch when the radiator fan kicks on usually while sitting at a light.

 

Thanks for the replies... I used to have a 300ZX and a rough idle always indicated something wrong. Didn't know if it was the same with the S2k.... I'm like a new parent, scared over the smallest things...

 

If you hook an accurate tach up to the engine you'll find that sometimes it idles at 800 RPM and sometimes at 900 RPM (It's obvious the ECU is targeting these #'s since the idle will "zero-in" on the target). I haven't figured out what the pattern is for when it seeks the different target but the effect I'm referring to has nothing to do with the A/C.

 

[QUOTE]Originally posted by S2KXTC
[B]I just got my S2k about 2 weeks ago and I am trying to make sure everything is okay.

 

idle will be higher (1-3k) when warming up and that is normal too.

 

I find that my S2k's idling behavior is identical to my (now gone) 97 Prelude.

Idle is held between 1500 and 2000 when the engine is cold. The idle lowers progressively until the engine warms up. Then it will be about 800.

It is common for the idle to lower during hard braking because engine power is required to maintain the vacuum. A crappy car (like the 91 Escort I used to have) can actually stall during hard braking. The S2K better not!

As for dipping, sure that's normal. Rev the engine, the RPMs fall and the computer has to "catch" it and add some gas to maintain 800. I have never had a stall in this situation.

Now, for the rough idle, here is something interesting. When the weather is hot, and the Honda is all pissed off and cranky (MAP sensor retarding your spark to the point of utter uselessness), the idle is niiiice and smoooth. However, I have noticed that a rough idle tends to be a sign that the engine is happy and ready to make good power. Sound crazy? That's *totally* the way it was with my Prelude. I actually learned to cherish the slight (and I emphesize slight) roughness as a sign that good engine response was to be had. I find the same with my S2K. Of course, that is not to be confised with an idle that is rough due to some malfunction.

-Dan