This happened to me in the beginning even when the engine was hot. I believe this has been discussed in the past. I think it is the map sensor???? But mine does not do it anymore. I had nothing replaced at all. I think this sensor adapts to your driving habits and automatically adjusts the rpm's. If you do a search on engine stall or something you may find reference to it.

 

happened to me...perfectly normal

 

Don't know if the same rules would be applied to an s2000 but with an Acura, a friend of mine, took his car into his mechanic and the mechanic had to go in and crack the idle speed cover off (for lack of better mech. words) , and then used a simple screw driver, he increased the idle speed of the engine from..1000-1300rpm to around 1500-1800rpm..

Now at low rpms, his integra does not shake, nor rattle ??

This may or may not work, but it is related somewhat I think ?

simon2000

 

Pretty normal. When it starts to get especially prevalent, I wiggle the wires coming out of the MAP sensor and it clears it up for a while.

 

I

 

When the rpm is going down.. it goes to may be 600 for a moment before climbing back up to normal.
I always though this was because the S2000 flywheels are a bit lighter than most cars or somthing.

 

This engine stumbling / stalling has been a problem for quite some time now. Is it normal? In my opinion, NO. However, a lot of S2000 owners have had this problem that it starts to become "normal."

In my case, the Xviper-Shingles-etc. thermal wrap has helped alleviate the problem. The stumble occurs when the ECU gets an out-of-range signal from the IAT sensor, normally when the weather is hot. Heat emanating from the radiator pre-heats the air entering the air box and goes all the way to throttle body where the IAT sensor is located.

Here are some threads that I started regarding the problem:

https://www.s2ki.com/forums/showthread.php?...ight=iat+sensor

https://www.s2ki.com/forums/showthread.php?...ight=iat+sensor

https://www.s2ki.com/forums/showthread.php?...ight=iat+sensor

https://www.s2ki.com/forums/showthread.php?...ht=rough+idling