Sorry viper maybe I didn't make myself clear with how I found out about the problem...............I didn't have to do anything goofy.....it's from everyday driving.

One example......going at 50km/h coming to a redlight, you would step on the brakes to slow down.....then put your gear into neutral as you are approaching the car in front of you as you are still braking to come to a complete stop...during the entire neutral time the rpm will rise to or drop to (depending on your engine speed at the time which depends greatly on which gear you were in) 2000 rpm and stay there even though I have already came to a complete stop....it will drop back to the idling speed of 1100 almost two seconds after I've come to a complete stop.

Another example would be me leaving in the morning for work. Because I live on a steep downhill once I disengage my e-brakes the car will roll down 2 blocks before I hit a stop sign where I would make a right to go into busy traffic. During that time when I'm rolling down the hill till the time I've came to a complete stop at the stop sign the rpm will rise from idling to 2000 rpm and it also would not drop to 1100 till 2 seconds after I've came to a complete stop.

So I'm not doing anything goofy.........sorry for my lack of imformation when I was describing the problem in my first post. Basically once the car is in motion the rpm will rise automatically and go from 1100 to almost 2100. This is very extreme by my standards.....the oem throttle bottle never did that and I've owned my car for over 3 yrs now. This problem is really annoying as my wife is threatening to do the voodoo dance as she is sacrificing my car to the GOD OF BARN FIRE!!!

 

Yes you are. You say you just roll in neutral two blocks down to a stop sign? With a cold car? I'd call that goofy and potentially quite dangerous.

 

Mike is correct. You are not driving a manual car in any "normal" fashion. You should not be rolling down a hill with the car in neutral. Also, most people will not throw the car into neutral well in advance of getting to the stop. I have a feeling that someone taught you some really strange stuff on how to drive a manual.

I would suggest that since we cannot determine whether or not it is your TB mod that caused (or aggravated it) this situation or if it's your odd driving style, you should meet up with some of the Vancouver guys and take one of the more knowledgeable owners for a ride in your car and show them what's going on and then have that person drive your car to see if the situation can be duplicated. For the time being, try the "MAP whack" and ECU reset. It might do wonders for you or do nothing. Most definately, your driving technique contributes to the issues you are currently having but it's hard to say if this is the sole reason.
I come out to Vancouver a couple of times a year to meet up with the S2000 owners. I'll be out next July, so maybe we can hook up then. Contact Geppetto. He's the Community Organizer out your way and he can tell you if they plan any meets this winter.

 

At great expense and effort, I went out to duplicate your driving style (the coasting in neutral thing). [I'm just kidding. I was out anyway. ]
With my stock TB, my rpm still went back down to the normal idle. Although this is still not the most ideal way to drive, I believe it has minimal effect on what's happening to your engine.
Some of the reasons why your idle may be acting up:
-Your TB may stay cold too long.
-You have a vacuum leak someplace.
This leads me to ask you a few things and since I have not seen this kind of TB, I'm working a bit blind here.
-Do you have a Hondata manifold gasket?
-Does this TB have the normal coolant jacket and if so, did the coolant lines get connected as they should have been or did they bypass the TB altogether?
-When they put on the TB, was there a gasket between the TB and manifold? If so, was it put on correctly and was the TB screwed on in an even fashion?

If you have a Hondata gasket, this would prevent the coolant from going into the TB and circulating in the Idle Air Control mechanism. This would also be true if the new TB did not have the coolant jacket or if the TB was bypassed and no coolant flow through it. The ECU would think that the TB, IAC and manifold was "cool" all the time and try to pick up the idle speed under certain conditions.

If you have a vacuum leak, then too much air is getting past the TB and confusing the IAC and MAP. Also, make sure that the throttle plate is closing fully and not leaking when closed.

There is also a slight possibility that the new TB makes it such that the TP sensor, MAP sensor and IAC are no longer able to do their jobs properly.

Like I've said before, do the "MAP whack" and ECU reset before taking any further steps.

 

To Mike:
I forgot to mention that before I roll down the hill every morning to work the car has already been warmed up and has 2 bars on the temp. gauge.....I always warm up my manual cars. And besides the 2 blocks are really short blocks. According to the trip odometer it's only 0.1 kms. (0.06 miles) So it takes me only about 10 seconds to roll down the hill.

To Viper:
I also do not put the car in neutral well in advance before I stop at a redlight......sorry for not putting down distance on my previous post...I just didn't think it was necesarry. I described the stop light neutral situation as in about 1-2 car's length before I hit the bumper of the car in front of me. By the time I put the gear in neutral the car is pretty much 2 seconds away from coming to a complete stop.

All the mechanics have test driven my car and 2 of them owns an S2000, 1 of the 2 owners tracks it on a weekly basis and they got the same result as me. No I do not have weird driving manual techniques as I only put the car in neutral right before I come to a complete stop at stop lights/stop signs and every morning down that really short hill.

I do not have the hondata headgasket.
What's a coolant jacket?
Yes I believe they did bypass the coolant.
Yes they used the same gasket that was used with the oem TB
I've done both the ECU resetting and the map sensor whack.
As for Vacuum leak I will give that a check tonight after work.
I believed from the beginning that it was the ECU that's raising my rpm whenever the car is in motion but I don't know why it is doing it.
As for meets I'll keep my heads up for the next one.

 

The point is more that rolling down the hill means you are 100% relying on your brakes to control your speed. Can be quite risky, especially with cold brakes.

However, I do habitually coast in neutral towards stop signs. Same thing, but with warm brakes. And I don't see my idle speed increase dramatically.

 

I have the Ericks TB 68-70mm fitted and have found no issues as described.
It is important to get the "Idle learning procedure" done as initially I did have idle problems.
Although my car has had also the inlet manifold "matched" coolant bypass mods, Toda cams and springs and Cai.

Have you had yours fitted to a standard car?

 

The stock throttle body has coolant running through it to help it warm up after a cold start (kinda like "carb heat" on an airplane). This coolant then runs through the lines that goes to the Idle Air Control system. If the coolant was bypassed and no coolant flows, then the IAC can have trouble stabilizing idle under certain conditions. Even an aftermarket throttle body should have these coolant passages. Hopefully, they were used.

 

I thought our idle was speed dependant. I know when I had the stock ECU and I pull up to a set of lights the idle would hold high for a second before dropping to 900. I thought this was a feature.

 

There could be a variation from one car to another. Mine will immediately go to idle speed as soon as I put the clutch in and take the gas off, regardless of speed. And after I come to a stop, nothing changes.
I do recall that on my Jeep Gr. Ch. it would hang up the rpm where I left it after putting in neutral and letting off the gas. Mind you, that was an automatic. Only after I came to a stop did the idle settle down.