1991 Gmc S15 (sonoma) Shakes When Idling & Accelerates Slow

[KuttyKool]

I just bought this truck last Monday and for the most part I'm happy with it (ask me if you want to see pictures) but I've noticed that it shakes when idling and it hangs in first gear for longer than I'm used to. It has 83,000+ miles. Now, I recently changed the air filter which help significantly with the shaking, but the truck still sometimes seems to be slow to change gears... maybe its because I used to drive a 1990 Cadillac Sedan Deville, which has 120-140 on the dash whereas this truck has only 80 on the dash (meaning that's just the way the truck drives) or this might be a real issue. Either way, I really hope this isn't a sign of things to come... I'm a real fan of preventative maintenance and only taking a vehicle to the car doctor in extreme cases. Anyone who drives or has driven an S10 or other truck from a comparable year, how did your truck shift... and what could I look at/do if you don't feel that its driving right. Thanks a lot for your suggestions.

 

By the way, I've typed enough already but I'm new on here... so if I've broken an unwritten rules I apologize.