Chevy woes

I have a 94 Chevy pu/s10 and have a problem maintaining speed. It seems to surge but smooths out when I accelerate or slow down. It has the Vortec 4.3 lt. engine. I also hear what sounds like the cooling fan is working overtime taking off from a light once it is warmed up. This makes my idle rather high.

btt

6 year old post and in the wrong forum!! If you want to continue this, post in the Chev S10 forum, thanks.