Automatic Box Holds Too High Gear/doesn't Change Down ( 6th Gen )

[Surrey Scientist]

I have a 1995 greyimport GT convertible, with 3s-GE engine and 4speed automatic box.

the gearbox is reluctant to down change and holds on to too high a gear for too long, although it will kick down if I push hard and long on the throttle.

If I switch to ECT-Pwr (power) mode it behaves more normally, and changes down much more easily and kicks down much more eagerly.

In "normal " mode however the car feels very sluggish.

I don't driv e it very often - its stored under a cover, and is only driven on long-runs on nice suny days, but I don't remember it being this sluggish in the past in "normal " mode.

I have given the gearbox several changes of a quality Dexron III and the fluid level is on the Max.

How do I go about diagnosing the problem, and are there any adjustments, tests I can make/do ?

[GT4 BOOSTER]

could be a blocked band????

pwr mode simply changes box from 4 speed to 3 speed. therefore it wont use 4th gear bands and works as it should. you really need an autobox specialist to diagnose it.