Engine problems???

Hi, My '93 Previa LE recently(a month or so) has a little hesitation when driving with the cold engine in the cold morning. It would drag about 1 to 2 seconds ( between shifting from

1 to 2) then hesitation going away. I don't feel it is from the tranny shifting. i feel the "instant stop" is from the engine. After warming up from driving, no problem at all. Running like a champ. Engine is smooth and quite at idle. Maybe it will turn out to be a major problem. Is it the computer mapping and control problem??I don't know?? Still observing and checking. Hopefully, my problem is a DIY correctable job for me. Regards, Matt