Replaced pick-up coil,ignition coil and crank position sensor.Will start then run fine for a day,week or more. Then,while running it will die.It will turn over, but it wont fire. Sit for a couple hours or a day,then starts. Plenty of fuel and compression, but no spark.

It's a bad ASD relay or a bad PCM (computer.) What's happening is when either one of these is getting hot, it stops working until it's cooled down.

It will do this sometimes after running 30 seconds. It usually happens in first 5 minutes. It will run for days/weeks sometimes no problem.

I agree with alloro- replace the ASD relay. PCM is another matter - lots of
good used ones out there if you look. Don't go out and buy a "rebuilt" like
I did and got the shaft for mass $$$. I'd also look at the grounds. My
intermittant problem on my Van ended up being both bad wiring (inside
the harness..left side of the motor between intake and valve cover) AND
a bad connector to the crank sensor. Crappy wiring on these years
Dodges - a trusted dealer told me MANY warranty problems. Keep looking;
you'll find the cause. Good Luck.