Well, it's over. Step by step it got better with the final step being a new MAP sensor from NAPA. The car has lots better response now, I guess the old one was on it's way out. I couldn't test it per the Volvo book as my hand held vacuum pump doesn't pump. Also, quite a bit of variability reported in price (and warranty) on these puppies. NAPA gives a 1 year warranty, same as Volvo, and the part is made by Echlin (~55 bucks), looks like good quality. The cheapest price was Auto Zone (Wells, at ~39 green ones), 30 day warranty. A Borg Warner was also available from a local place at ~46 fat ones, no warranty. The 55 handily beat my dealer's 115 with alleged discount. I was eventually able to track it with a P/N, but its just easier to ask for a MAP sensor for a 90 Chevy Celebrity w/a 3.1 liter engine.

Thanks to Spook, Summerduckman and the rest for helping me with this PIA.

Later,

Mike