1990 e250 starts rough chugs and will stall in Damp and cold weather. I've changed the plugs, wires ,cap n rotor, fuel pump and filter, along with iac valve that was black!
First off I am a Yooper & live here, there what ever, but it sounds like you need a tune up as moister is affecting the ignition system, plugs, wires, rotor cap, possible coil...
You could have a sensor that is giving a misread to the ECM, as this is a Ford OBD1 a breakout box is needed for this operation if there is no check engine light. You might consider pulling the codes first, hopefully there will be some in memory that can give you a place to start. Go to:http://straighttalkautomotive.com/OBD1/ford-OBD-I.html
Sorry I didn't read all the question I was distracted, but as far as sensors, the number 1 sensor that causes grief with everything else would be the temperature sending unit, even though you gage reads properly. It affects the AIC valve, & TPS by sending bad info so to speak to the ECM that controls all the sensors. Your thermostat should be in working order so the engine can reach operating temp. for the sensors to work properly.
Looking for a Used E-250 in your area?
CarGurus has 53 nationwide E-250 listings starting at $1,295.
Search Ford E-250 Questions
Ford E-250 Experts