question about idle issue

The idling goes up and down on its own when first starting up. This happens even after cleaning the mass airflow sensor

Hi Scotty,
Love the videos! This is my go to youtube channel! Anyway, my question is, my friends 2007 Ford Explorer, when you start it it idles really low and then revs up and down on its own, we cleaned the mass airflow sensor and it didn’t do anything, what do you think it could be?

I had a similar problem on a Cherokee and a Toyota, in both cases it was the crank position sensor.