The car jerks when going into 2nd gear and just revs when trying to reach 3rd gear. Is this due to the vacuum modulator and where is this located?
Transmission vacuum modulator on 1996 Ford Taurus
does not have one. it is electronically controlled. you have had an internal failure and the unit needs to come out and re built. sorry for the bad news.
ck your turbine speed sensor on the back of trans by the left wheel well,could be unplugged or sensor is bad good luck