I have an 88 supra N/A with an automatic transmission. The car started shitfting at 5000 RPM two months ago. I did reset some fuses, replaced the transmission fluid, change the ECT unit box still did not help, I finally replace the transmission and the torque converter yesterday, the car still change gear every 5000 RPM. I just cant think of anything else to check on the car. I will appreciate any advice.