I think this subject has been broached over and over again but nothing I have read so far has helped me cure my problem. So here goes...... Rev the engine and when it returns to idle the engine sometimes shudders as the revs drop to around 60r7k for a second. Same thing happens when I pull away without giving it plenty of revs.
I have set the TPS to as near to 6% as possible (5.9%) I have thoroughly stripped and cleaned the IAC valve. I have replaces the MAP sensor and thoroughly
cleaned the throttle body and adjusted the throttle cable. I have re-learned the ECU god knows how many times and my code reader shows no fault codes. Both O2 sensors read between 0-1volt. The car has 54,000 miles and otherwise runs fine, on the cam and off (VTEC). Valve clearances also double checked. It has done this since I purchased it 3 years ago and I would really love to finally sort out the problem once and for all. It seems odd that it does not do it every time the engine returns to idle. Please help!

https://www.youtube.com/watch?v=4dd_...ature=youtu.be

 

clean engine grounds? check for vac leak? stuck injector?

if it was my car i would add an extra ground. and soak injectors in seafoam overnight to rule out grounding and injectors.
have ever considered deletin the iac?......

 

This is lovingly known as the S2000 "shutter". Happens with all of the AP1 engines. Not sure about the AP2 as they are inferior.