Okay, I've read up on the 'acceleration enrichment circuit', and it makes sense that my problem could be in this circuit. But it will probably be several days before I can really get into it. I suppose that in order to trouble-shoot this circuit that I am going to need to get a T-adapter for my vacuum gauge. It looks like my problem could be: 1) a bad thermal vacuum control valve 2) a bad delay valve or 3) a bad control pressure regulator (again). or 4) a clogged or leaking vacuum hose in this system. I'll keep you posted on my progress. In the mean time, do y'all have any suggestions? Believe it or not, I actually had a clog in a vacuum hose on a GM car. I couldn't believe it. I had to cut the hose open to see what it was. What I found looked like the end of a plastic golf ball 'T' that may have broken off inside while someone plugged the end of the hose to do a diagnostic. Later, Walt Tampa, FL Delorean mechanic apprentice