2000 caravan 3.0 stall after 20 min no spark restarts few hours later

Don't know this car. Check fuel pressure with a fuel pressure gauge- if correct, not a problem with the pump. Also make sure the pressure will hold for some time with key off. It should hold pressure for several minutes, maybe 20 minutes, some maybe a bit less, but it must hold pressure for a time. If pressure is good, check for spark when it won't restart. If spark is lost, suspect the crank position sensor.

Was a recall on Ford trucks. Ask Fird dealer

which engine>>
so you have 20 mins to find the cause, not sit and drink beer.
check for spark.
on all cylinders........ using the 100 year old way, we all should know.
ok say spark is good (if bad , scan it while bad, bingo got DTC>?)
sparks good
i NEXT use test fuel.
it starts and runs
it starts and stalls in 3sc
or does nothing
IN this order, unless want to do compression test hot fail.
watch scotty , do his magic. (100 years old this, magic, now.)

http://www.youtube.com/watch?v=064Ilsz8Fzg&NR=1&feature=fvwp

Did they figure out if you are loosing fuel or spark when it fails to start up ? You would need to know which to proceed.

Check your coolant level and overflow bottle for proper fill. Or try running it With radiator cap loose to see if it still stalls. If it still stalls and coolant levels are good you need to check temp sensor. May be more than One. If you did install a new one, it may have been faulty or damaged. If all that fails then try an idle positioning sensor. The spring may be worn.

are yougetting any codes could be a number of things really weak battery,alternator,something in emmissions, clogged catalytic convertor.and o2 sensor gone bad

sounds like the alternator is cookd to me
use the yellos to call the salvageyard

Replace the fuel pump relay, it's easy and cheap.

it could be your oxygen sensors are going bad

Sounds like a crank sensor.