Shaky idle for approx. 30sec

[greentea]

All, thanks for looking. Just a month ago, my M44 engine w/ the air pump started shaky idling right after COLD start. Absolutely no issue on warm start. It does not stall but really annoying. Once passed 30sec or so, idle seems stable as it should. There is no issue or whatsoever in gas mileage and performance. Thus far. I replaced:[*]ICV[*]TPS[*]Temp sensor attached to the head I will rule out vacuum leak because the engine will be shaky all the time if that's the case. No CEL staying on. Cannot diagnose with my scanner. Anyone any ideas?

[paul somlo]

I've dealt with that on and off for about 16 of the twenty years I've owned my 'ti. Happens a few times a year, warm or cold, never figured it out.