Ok, I've seen lots of information on here on how to get the TCC switch to manually trip, but nothing on the issue I am having.
The transmission shifts into overdrive (4th), but never locks-up. The RPM's will drop until you press on the throttle, they will then go up. If I shift into 3rd, RPM's go up even further. I have replaced the TCC solenoid but no change. This transmission and torque converter was built by Coan back in 1989 and driven for about 10,000 miles. The car was crashed, and over the next 15 years was only driven about a total of 100 miles. The transmission shifts from first to second hard, most the time shifting from 2nd to 3rd the RPM's go up between the gears, other times it shifts fine.
I just recently swapped in this transmission and a 383 motor with 52mm tpi. The car was originally a tpi 305 with a 700R4 that shifted fine when I pulled it out.
Is the torque converter bad or could it be something else? I've heard that the plates in the tc can dry out, but there was nothing in the tranny pan.
Thanks everyone. I've already learned a lot off this web site.

 

Forgot to say, this setup is now in a 1991 Trans Am with a hypertech chip for the 305. Knock sensor is for the 305, also using the MAP setup, not MAF.

 

Maybe a defective pressure switch

 

X2 the pressure switch, but before you buy a new one, check to see if the press. switch connector has good contact with the terminal end on the switch. The connectors wear with age and get a little loose. It could cause a no lock-up scenario or an intermittent lock/unlock cycling of the TCC. The latter scenario happened to my original 700R4. I thought my converter or solenoid was bad. If you have to get a new switch though, no problem, they are pretty cheap.

 

All right, went to the dealer yester day to see about getting a new pressure switch. They list one for the 5.7 and one for the 5.0. I ordered both, as total they are only $20. I will swamp the 5.0L one in this weekend and see what I get.