To refresh, stalling on quick stops prompted me to research why the frequency valve had been unplugged. I found with the help of members here, especially ctaylor (thanks Chuck) a bad ground (at the connector) on the warm up compensator. I was totally frustrated to find I still had the original problem, so I got back to basics and pulled a spark plug, (as another member mentioned, but I was stubborn) and found a basically new plug to be badly fouled...rich mixture. I figured this had occured with the WU comp out, so I cleaned them and was going to check gap, since I didn't remember gapping the plugs when I installed them. Unable to find gapping specs in my owner's manual, I came to this forum, my new home on the internet

, to find spark plug gap as recommended by our members.......and found the threads about platinum plugs, which is what I installed when I bought the car

. I promptly put in a fresh set of Bosch W9CD Supers and I'm happy to report the SL is back! Fast idle cold, no hesitation, though the on/off stays at about 15%, it seems the controller has gone to controller heaven, as it doesn't change with engine temperature. Regardless, happy camper here. A big hearty thanks to everyone here for their generous help.
Paul