Hello there, 2 days ago i tried to ride my mk2 but rpm was jumping up and down from 500 up to 1500 and car did stall, tried to give a gas and rpm still was going down to 500rpm. Today everthing was fine for 5 minutes till i started to press on gas pedal and it started doing it again. What can be cause of that and how could i fix it. Car has 1.8 mono engine