HELP 4L60E and weird shifting issue
ok so i have a built trans and the trans shifts fine. yet when i slow down go around a corner or dont come all the way to a dead stop at a light or something it wont shift. it goes down to first i think but wont go faster than like 15 mph. yet if i come up to a light or a stop sign and make a stop 100 percent and then go shift fine. does this make sense? 


