1989 Prelude Auto Trans. problems

My honda prelude is very screwed up at the moment.its an 89 si (dohc) and the automatic transmission loves to stay in second gear.it usually only shifts to third gear if i red line it and then it will immediatley return to second.i have fooled around with the throttle valve cable but it only shifts correctly for a few miles and then messes up again.i have heard everything(but not exactly) from a fried solenoid to junking the whole car.anybody got a clue?let me know.any info is greatly appreciated.


Aaron