ok I have a 94 3000gt auto here is my problem my overdrive will not kick in when i get up to speed it will try to kick in then it just revs way up and won't go anymore so it does shift out of third but there is nothing there. There were not any problems before this it just up and stopped working one day no slipping of any kind before this happen. Any answers or suggestions would be great

 

relay....solinoid and or solinoid pack last time you changed fluid and filter and what fluid did you use if you did change it ...fuses