1997 Miata is sluggish at low rpm, occasionally idles low and shakes

So far so good. I've driven it everyday and the clean IAC seems to have solved the issue. I'll check back in a month to give it the confirmed fix!

I started it after running the car a while (engine was warm), with AC on and it was a fairly hot day 85* or so. Car idled roughly at 200rpm for about 10 seconds then caught up and started running fine. Any more ideas? Could it have had bad gas in the past? Semi clogged injectors? It seems to only happen at start up.

Any codes or pending codes? I had an occasional rough idle, barely rough enough to notice it, on my '96 Miata. That went away when I replaced either the PCV valve or cleaned the EGR valve. 

If I'm in your position, I'd be throwing $20 and 30 minutes at the problem in the form of cleaning the EGR valve and replacing the PCV and any hoses associated with the PCV and EGR. I'd also consider a seafoam treatment. 

No codes. Thanks mtn! I'll get on it! 

Hey guys, replaced the PCV and still have idle issues on hot days. Again, it's not every time I start the car, but the hotter it is out, the more likely it is to stumble at idle for 10-60 seconds.

I did an amateur vacuum leak check with throttle body cleaner but no change in revs on any of the hoses.

I will mess with the EGR next.

Is there a EGR removal and cleaning video or write up for dummies? Looks tough to get to.

I unplugged the EGR and it started right up no issues (except CEL).

I will just throw this out there. I was experiencing a similar condition with my 99. It was the coil pack. One of the spark plug wires was not making good contact inside the coil tower and had melted the insulator. It was not making contact when cold and sometimes while driving. This created a dead miss condition that could be construed as a rough idle/stumble. Easy to check, remove the wires and using a light inspect inside the towers.

Time will tell, but I think cleaning out the EGR valve fixed the issue. I just ran the car pretty hard, got it hot, then started it back up. No idle issues. Thank you guys!