ok, im a student at my high schools auto shop. this is my 2nd tranny swap on my truck, however this time when i installed everything seemed fine i ran it through gears as i was installing tranny fluid. (filled with 5 quarts first) when off lift tranny worked and speedometer reached 35 mph. however when i was taking out of our shop it kept stalling in gear, i thought it was a vacuum line however after looking over it nothing was missing. my overdrive light keeps flashing on my shifter lever. so this is making me believe its something electrical. the tranny i put in was out of a use 94 ford f150 with same I6 engine. so it seems that whenever i put my tranny under a load it just stalls out, is this tranny issue, electrical issue or fuel issue. i have a 1993 f-150 I6 4.9L

 

all fixed. issue was with one of the electrical plugs on the transmisson. it was making the engine stall out wasnt a fuel issue or anything. hope this will help others with same issue