xviper

Understood. I don't "think" the misfire thing has anything to do with this. It would seem that it is directly connected to you turning the A/C ON. Check stuff that's already been noted here.

Gregg Lee

No. take it to Honda and show them the symptoms.

S2kracka

How bad is the vibration? It may just be from the A/C putting more strain on the engine and bringing the RPM's down slightly. Does the vibration go away as soon as you give the engine a little gas to raise the RPM's by a few hundred?

Amer

Yes, vibration goes away with tapping the gas.

notfastenough

Did you find a resolution to this? I have a simmilar problem except I get a violent shake when the compressor first comes on and then once the engine catches up, it stops. But it does do this every time the compressor cycles on only at idle.

jert534

Mine is like this too....when Im driving and I get off the clutch the revs will dip below 1000, to about 300 or so and the car will vibrate like its gonna stall and it just goes back to 1000 after a second or two...

I tried the map sensor whack and it didnt really help now Im trying to find out how to clean my IAC motor.

I think hes having the same problem that most people have when their RPMs dip below 1000 and shakes like its gonna stall, but it only happens when he has the AC on.

xviper

The OP's problem is slightly different from yours. His is when the A/C compressor cycles on and the pulley clutch locks. The engine can't seem to be able to take the sudden, added load. His may be a compressor problem (abnormal load) that is compounded by the dipping idle problem.

Yours is different in that your A/C may already be locked on but when you come to a stop, the engine idle dips even more than when the A/C is not on. Again, this is in keeping with the dipping idle thing that virtual all S2000s suffer during the hot days. The "normal" added load of the A/C compressor aggravates it. Although the 2 sound similar, they are subtly different. I have experienced this same thing for years on my car. It seems each time I use my A/C (and I don't use it often), it will do the near stall, dipping idle thing. If I leave it alone, the ECU seems to figure it out after a few stops and won't do it anymore till the next time I use the A/C (sometimes it won't do it again). Cleaning the intake manifold area may or may not be a cure. My car is nearly 6 years old and I have never cleaned my intake manifold or throttle body or IAC system. It always seems to be able to compensate for idle if given the chance. As long as it doesn't actually stall, there is really no need to worry about it.

jert534

It sucks being in a extremely hot environment, my car has stalled twice when it was 115+ with the AC on

DryCycle

My 2004 does one of the same things. When the A/C compressor cycles on, the idle drops, and the car shudders, vibrates, etc. until the AC cycles back off again.

Is there a way to set the minimum idle speed?

jyeung528

any updates fro the OP?