Eric in Dallas

My '73 2.0FI idle collapses when the engine gets very hot (hwy speed, 90F Texas weather). It falls from 1000 rpm to just barely running and smells rich though turning the ECU richer brings idle up. I disconnected the (new) vacuum advance on the retard side (leaving advance in place) and that solved it except for very very hot conditions or hot start after 10 min engine off. Timing is set to spec. Should I add some advance to idle?
Does same thing with different pressure sensor or ECU. Pressure regulator held at spec for over 30 min. New head temp sensor.