Will not go into 1st gear without shifting into neutral first, I can get it to start in 2nd if manualy selected and up-shift from there. This is a recent problem after the first occurance, I installed a Trasgo kit. Now I think I have mutiple problems #1 GOV PRES SENCER solonide, #2 higher line pressure. This is an intermittent problem more offten than not but intermittent. Should I install a resister on PIN 31? Or should I replace the GOV PRES Sencer?

 

I have a same problem when i installed Trans go Kitt. My problem was loose wire in converter clutch solenoid. (Is in valve body 2 pieces). measure with ohm meter both solenoids in valve body! My problems were just at same as you!
Easy to fix just reconnect loosen wire to tin solder.