Any ideas?

engine used to start/run fine, then a couple of months ago, once the engine warmed up, at idle, the check engine light would come on and the rpms would go down to about 1000, then surge back up to about 2000 then go back down and continue to bounce between the two. yesterday it started rough and it felt like a cylinder wasnt' firing while driving. an hour later i tried starting it again and it wouldn't start. the battery wasnt' dead but when i jumped it i got it to start, but again felt like it wasn't running on all cylinders. as far as the engine surging up and down i've heard maybe a vacuum leak because my cruise control no longer works, and i've heard maybe bad pickup coil for the no start and missing. do these sound like possible solutions? or is God just smiting me?
thankyou all for your time and help

sounds like a vacuum leak or bad egr or egr tube, those crack when they are old. and the coil sounds right for the hard start and missing

could also be tps throtle position sensor

finally got a weekend with the temp above freezing to work on her, and you're both right. the pickup coil was shot with no insolation left whatsoever. changed that, engine started right up, idiot light was still on code 21- tps was stuck. thanks a lot guys

sweet!! glad we could help out.