Aside from the AFM and TPS, what temperature-sensitive sensor affects fuel mixture? I noticed that my acceleration/hesitation problems are directly related to how warm the engine is. Almost as though the sensor is slow... because my warmup cycle lasts even past when my temp gauge reaches halfway. Thermostat? Water thermosensor?

BOOOOO!

 

intake temp sensor (2, one in AFM, one in intake manifold), water temp sensor (water pump housing)

warmup is mech. (thermowax)

check your codes
http://www.1300cc.com/howto/how2/codes.html

 

The ECU's coolant thermosensor is a likely culprit. It's mounted on the rear of the waterpump housing.