dammdest thing,,,I turned in the screw (tps I think) four turns clockwise and now it idles almost perfectly,,,,,it's some gadget just above the thermostat housing on the block in front of the carb....oh well,,,,go figure....i remember removing it to do the mech secondaries mod,,,,

 

If the problem persists I'd say you'll need to check your charging system including the battery. in fact I would suspect that's what it was, because as was said earlier the alternator supplies the system when the car is running- true,but it does so through the battery. So if the battery is very weak or obsorbing an excess amount of the charge it will effect other things in your system (like lights)

PK797 NYC