Help!!!! 1990Q sudden transmission problem

[JDM90Q45]

Recently my 1990 Q45 WHICH RUNS 100% NO CHECK ENGINE after extensive repairs and complete harness connector cleaning started slipping in all gears after stop. Seems like when I stop at a light and go to takeoff the transmission locks into nuetral and wont respond to shifting in an gear except park. When I shut it off and restart all gears engaged but after deccelerating same slipping no drive force almost like its stuck in neutral? I love this car and have spent countless hours and money to restore, I have had 2 J30s with all of miles and never had a problem. Anyone have an ideas besides a swap? Could this be a TCU problem? Fluid is clean and always added. Lucas treatment. When changed. Please help if you can, thanks.

[Q451990]

Were the "extensive repairs and connector cleaning" before or after the problem started?

I would run the transmission self check in the Factory Service Manual - http://www.nicoclub.com/FSM/ - and see if you get any results from that. If there's an electrical issue it should point you in the right direction. TCU failure is very rare - in fact I don't think I've heard of it ever happening. How many miles are on your transmission? From what I can tell the typical transmission failure starts with it not wanting to go into R or back into D after being in R.

Good luck!

Heath

[JDM90Q45]

I fell in love with the car I bought it after it was sitting for a year. I ran codes and diagnostic w and found bad injectors, and several codes to sensors due to bad connections apparantly. Fixed it and drove it for 3 days no issues no lights I thought it was a strong transmission it shifted perfectly under normal and better under heavy gas at highway speed. I qs very surprised by the power! Day 3 I was at a red light and I went to leave and it as like it was in neutral no gears worked except park. I shut it off and restarted and it went nto gear fine and took off no slip. This happened. 4-5 times and then I parked it . It's a 90 with 201,000 miles...I've been poking around seen the cooler for transmission is weak and it was 98 degrees for two days I was driving the car. The AC ran perfectly and everything was good and next day busted. IDK