95-s10 with new problems

My trruck has ran great since i got it last summer. Its a 95 s-10 4x4 with 4.3L and a five speed. But today i took it to the store, when i tried to start it the idle was real ruff like a miss fire a gave it a couple quick revs wich were both choppy then it smoothed out ran fine all the way home except it usually idles about 850 and it wouldnt drop under 1300. this went away the next time i started it except it still felt like it was missing but idle was right couple quick revs and it smoothed out again.
later on i went to a buddy's house and let the truck sit for a copuple hours. when i went to start it just made some clunking noises like the starter was trying to engage but couldnt so we pushed started it. when it fired up the exhasut had a sweet smell to it my buddy noticed it too. It almost smelt like antifreeze. the smell went away to fast to tell though. After i got the truck home it started just fine, starter could be on its way out though or atleast the soilenoid. Any way i checked the oil wich was recently chaged its clean. checked the antifreeze its full and clean. did a tune up about a month or two ago I dont reacall changing the pcv valve though. any way sorry for the novel. But if anyone might be able to help me out i would greatly appreciate it.

tuneup ever?

Try PCV (really cheap) and EGR