Ok so I thought I would buy a new idle air valve since I was having occasionally where my 93 XJS would stall when I would back up and stop right after start up. Also, some big dummy ripped the old one apart (not gently by the way). I looked around and found an off brand one on Amazon that said it was for an XJ6 but says it fits my 4.0. I put it on and fired it up. The engine fired right up, but started fluctuating the rim from idle to a much higher rpm (I was outside of the car and didn’t think to look how high it was). I took it back off and looked at my old one. I had unscrewed the end of my old one before (remember I was rough with it) I screwed it all the way back in and compared them. They were almost exactly the same except the tip was a little bigger on the new one, but looked like it would still close the hole just fine. I installed it back in and fired it up and it started doing the fluctuations! Has anyone else had this? Do the need adjusted somehow?

 

Ok so I just found a reference on how to set it! I'll try tomorrow 😊