My zx has been missing at about 3000 rpms. I took it to Test Only Smog and still passed, for some reason. The car passed to my suprise. It passed all the tests by a considerable amount. This leads to my question, and yes I already did the obvious-New injectors, distributor-83zx, msd2 coil, new airflow meter, vac advance, oxygen and tp sensors, cap, rotor, wires, set timming, adjusted valves and swapped ignition modules... and still the same. I have noticed that when it is cold it seems to miss less. I also noticed that the cyl. head sensor has some black, sludge like stuff were the connector meets the senor,not the connector inside they are making coonection. Can anyone identify the sensors in the tnermostat housing I checked the archives but cant find, I have on the top right -thermo-time(injector type w/ large nut) top left-one wire sensor w/butt connector black wire?, bottom left-sensor w/ butt connector wire color yellow? Can this cyl. head sensor cause ingnition retarding? Could the regulator or anything else be the problem? Thanks!