3100 rpm @100 km/h- too high?

Ive been searching around, but ive found nothing hopefully someone here can help me. Recently Ive noticed it seems my 93 auto tercel has had pretty high rpms. I honestly dont remember what it was running at before, but i dont think it was this high(3100 rpm @ 100 km/h). It has always idled high(1800rpm or so), and Ive been told I should get the timing checked, but could this also cause high driving rpm? All ive done recently are change the spark plugs, and I change the oil regularly. Thanks in advance