Idle Rpm going up and down when ac is turned on

[Ribopaido]

Hello everyone

At idle when I turn clima on , rpm go up to 1300 then drop steadily while ac works and cold air is coming out. After 2-3  seconds Rpm drop down to 400 , ac is turned off  then boosts back to 1000 and ac producing cold air , and same thing goes on. I know I have an issue with really bad gasoline that caused cut-offs and slow acceleration but after getting 6lt of 100 octane fuel while tank was 60% full , it got so much betterbetter  so I'm waiting to burn it up to reserve and then fill it with premium . My mechanic suspected  the spark plug wires but the DIS is directly connected to the spark plug ( the car  went through a complete check and service) so it may also be faulty. I think there a possibility it is low on refrigerant and when the pressure goes up rpm drop and the unit shuts down or the fuel can cause issues like that but anyone has any previous experience?

Thanx in advance

[Ribopaido]

Edit:  Problem for the AC was the LTFT due to bad gasoline , cutoffs and clima work super now. Please be careful of the gas station u fill up to.