When driving on the highway. My torque converter didn't seem like it wanted to lockup at all. Today it locked up while on the highway, but wouldn't unlock. Even if I slowed down and accelerated it would instantlly lock when it hit 4th. Later on it would lockup then a little while later unlock for a few miles before re locking.. Any ideas?

 

BTW I just did the converter and shift kit last weekend. That is when it started. Will retuning it fix this?

 

Assuming it was a good install the new converter with higher stall than stock would love a retune I bet! Although it should act more consistent, even if it's not acting the way you like.