Chrysler: starting problems

Question
I have a 1996 Chrysler Concorde 3.5 w/ 150K on her.  Problem is:  when I start w/ temp around 50 or above it starts great.  After driving for awhile, shutting off engine for 10 minutes or less it starts up again fine.  If longer than maybe 20 minutes it will turn over for exceptional time ( 5 to 10 sec.)   If it is colder than say 40F start times are too long also, very cold is worse.
I have replaced fuel pump, filter, injectors, plugs, wires, air and water sensors on top of engine and intake gaskets.
Battery is also new, old one died.
Thank you in advance, I'd like to continue driving this car as it was my Mothers, reminds me of her.

Answer
Try using the ignition key to get a fault code readout: turn it "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by a 4-digit number preceded by P. Let me know it if so. If that doesn't happen then do same key routing only watch the check engine light which remains "on" to see if begin to flash, pause, flash, etc. count the number of flashes before each pause. Then repeat the process to be sure of an accurate set of flash counts. Let me know the counts in the order of appearance.
Roland