Howdy guys. One of my buddies is dealing with a 1990 3800 stock drivetrain, so throw in a 4T60 (not an E). His fluid level is good and he replaced the shift modulator to try to cure this problem, but did really improve it. Here'* his issue according to him...

it doesnt shift into second, it stays in 1st, and once you get it goin up to 15-20 it acts as if in nuetral and pressing the gas does nothing but keep the rpm'* up, doesnt speed the car up. eventually after the car warms ta to lines it will start acting normal, or if I bassicly floor it to like 30-35 it then will shift and act normal

Any help'* appreciated. Thanks guys

2nd gear clutches are worn. That'* typically the first thing to go on a high-mileage 60. A full trans flush may help for awhile.