I have done some work on the s2k the past few weeks: Ap2 retainers (mine is an '02), Oil jet bolts, hondata gasket, 70mm Tb from B-series. Car runs fine but I have trouble figuring out its high idle. It idles fine when the car is a zero mph, but goes up to 2.1-2.2k as soon as the speedometer reads 2mph or higher. Here is what I tried so far:

-Disconnect TPS to see if it gets fixed
-disconnect IACV to see if it gets fixed
-Do idle relearn procedure
-check for vacuum leaks

The high idle is speed dependent only, it is not dependent on load (sound system, head lights, air con, etc.)

 

I could adjust the adjustment screw on the TB to idle normal, but then when I turn on AC or the fans turn on the car basically dies. When I adjust it so idles normal while AC is on, then it idles at 2k rpm until I reach zero mph. When I disconnect the IACV while the engine is running the rpms shoot to 4k rpm and I can't make them die down.

Anyone else with Large Tb could share how they got around this? I have Emanage Ultimate as tuning software.

 

You're saying that when coasting in neutral it revs at 2200, and doesn't drop down to normal until a full stop? So, for example, if it were sitting in your driveway idling normally in neutral, and you pushed it forward (or backward?) a few feet, the revs would suddenly jump up?

 

Warm up the car, unplug the IACV. Adjust the idle to 850 via the throttle idle screw, with all accessories, ac radio and headlights off.

Then wait until the engine is cool, reset the ecu and perform an idle relearn.

Same way you would on a d/b/h series with a set screw, you unplug the iacv, set the idle screw, reset ecu, plug in iacv, wait til cold, then idle relearn.

 

Yes exactly like that.

 

It didn't work for me. The car would learn the idle, but as soon as I got going it would raise the revs.

 

are you positive you did exactly that(unplug the iacv sensor), adjust idle, shut down, and wait for a full cold, reset, plug in iacv, then idle relearn and do not drive during the idle relearn with all accessories off? allowing 3 fan cycles after completely warm? once 3 fan cycles go off, turn on headlamps, radio, and ac, and take it for a few minute drive.

 

This seems super bizarre to me. What does vehicle speed have to do with idle? Does the ECM actually use the VSS signal to trim the engine (air/fuel/ignition), either at idle or under load?

OP, are you sure the B-series TB is a drop-in replacement (all sensors will work as usual, signal wiring is the same, etc)? If you have the original TB I'd put it back temporarily just to see if that solves it.

 

Only thing I can think of is when your stopped you are using the brakes which affects vacuum system

 

You may need to check that the TPS is calibrated.
https://www.s2ki.com/forums/s2000-un...oltage-289750/