I have an 88 pickup 22r & it has a funky idle where it goes up & then down over & over no vacuum leaks & changed the distributor I thought it could of been the advance but I ran the vacuum line back to the vsv & when disconnected doesn’t do the idle issue & when connected it does no vacuum leak there neither but when I turn the ac on the idle goes back to normal any one have any ideas could the vsv just be bad & needs a replacement?