hi. i was wondering what the diesel rangers were like? is it worth my while buying one? or would i be wasting my money?

What year Ranger ? I did not know they sold the Ranger with the Diesel in the US yet ?
Just overseas.

it a 1985. they only did it for a couple years

It depends on the condition of that 85 Ranger....
If it still looks good and can perform well... Then go for it!

Aside from checking the overall condition, consider the price before buying one.