Yup, I still have my OTC Monitor 2000 from way back when. I don't recall and it's kind of fuzzy but 84 may have been the first year of the computer controlled carburetor it had a solenoid that would adjust the mixture at idle it had a little blue connector that drove the solenoid I want to say my Mom's old 84' Caprice Estate Wagon (complete with woody wagon side stickers) had it I know 87' they all had it for sure.

Jeff