Engine idle jumps then settles on 4L

I bought a 97 wrangler sport with a 4L. The idle jumps from about 900rpm to 1500rpm while in park.
It almost seems like a miss fire on one of the cylinders and then the idle jumps up as a reaction to the miss. While I am driving, the miss will happen and it always happens every 10 seconds or so. Very predictable. I have replaced the tps sensor. Checked all the injectors. Replaced the intake/exhaust gasket. Checked all the vacuum lines. My next guess is the ECM.
Thoughts?
Here is a video while at idle...
https://youtu.be/uZYasBYXO7M

 

I'm thinking the idle air control valve needs cleaning. If you had an engine miss then it should give off a code stating so.

 

Sorry I forgot to mention that I replaced that as well.

 

Listening to the video, which really helps, it sounds like the idle speed is quite low. Then the idle air control valve kicks in and the idle speed goes up. Usually a cleaning of the iac will solve the problem like that, but what about its mating surface in the throttle body? like is that clean? If you could get a scanner on it that might give you a better look at the problem.

 

Do you have a check engine light on? How long has it been doing this and did it start all at once or got worse over time? Even a $150 scanner will give you live data which will tell you a lot. I would check basic stuff first like battery connections and sparks/cap rotor and wires. It’s hard to say on yours but I had one do this same thing and the spark plugs were .120 gap. Good luck

 

I've checked all the plugs and gap. I checked the throttle body where the iac mates and that is clean. Battery connections are clean and tight.
Probably running it into a guy to have it scanned....