Recent starting problems on my DD Need ideas!!

Ok first off i have a bone stock 98 sport with 150,000mi. It has been a great vehicle for the last couple years. Well in the last 2-3 days i have got a no start on the first try of cranking. Its acts like i didn't try to crank long enough but i always do, so this happened 4-5 times. and then today i fired it up at work and headed home, i stopped at the gas station and filled her up. Went to start it and it did the same as above. so i try it again and this time it just cranks. no starting at all not even a backfire. well i try 4 times cranking and nothing then on the 5th time i push the pedal down and it fires up but then dies out as it comes to idle. it did that twice so i modulated the pedal to keep it running then i let off and it idled fine. so i made the 40mi trek home with no issues and it started fine a couple times once i got home.

So now im confused. I have read around about the CPS could be a culprit but you would think it still wouldn't start even though i gave it gas ( which in a EFI vehicle is really just opening the throttle blade).

and then on a side note, not knowing if this is anyway related but in the last month i get a plastic burning smell inside the jeep when i run the heat. i would say its coming in though the vent from the engine bay..

Thanks and sorry for the long postaperwork

i would say cps.

when it doesnt start, is it getting fuel or spark?

well unfortunatly i haven't been able to check yet. When it began this not starting crap it would always start on the second try untill today. Im worried about getting stranded or not making it in to work tomorrow if it doesn't start..

and wouldn't you figure it started just fine all day today