I got a 85 trans am with a 305tpi and a 700r4. It shifts really fast you under light throttle it goes into OD at 30-35mph and then just lugs around it won't down shift into 3 unless you floor it. Is this normal for these cars? And I already adjusted the tv cable with really no changes at all.

 

it's gotta be your tb cable, it's kinda tricky, make sure there is no slack in the line between the part by the tpi and the transmission, if it looks good, just push it in one more notch.

 

I have the same thing with my 92. I was told it was a "spring" behind the valve body. I wish I could describe this better, but it would cost me over 300 dollars to fix. I just manually shift from 2nd on up. It shifts nice and firm. It's not related to the tv cable.

It's no sweat off my back though. I hardly ever just put it in gear and drive with any auto. They never shift when I want them to.

When you manually shift manually, how does it shift? Is it soft and mushy, or firm?

 

I would say its right in between its not really soft but its not hard either. I also pushed the tv cable as far in as it would go with no throttle it shifted a lot better after that but if I ever wanted to floor it it would adjust itself

 

It sounds like you problem is not related to the tv cable, but you should have the transmission looked at by an out fit you can trust. Until then I recommend manually shift.