I have 2008 Grand Caravan SXT with 3.8 liter engine. Starting this summer an intermittent long crank time with rough starting presented itself and now a misfire is being reported on cylinder 1. Long crank time mostly happens in the morning and misfire goes away after driving a few seconds and run fine. If the temp is 20 degrees or lower the misfire does happen as often.

I have check the fuel pump relay and that tested good.

I have did a fuel pressure test (ran pressure test twice). I connected the pressure gauge before the fuel rail.

Initial pressure 55 and 59 (ran pressure test twice) after cycling key on/off twice and got 59 with engine running.
Leak down: in 5 minutes pressure drop to 30 and 32
in 15 minutes pressure drop to 10 and 12
pressure was still dropping after 15 minutes, I just stopped the tests.

Does the pressure test indicate a check valve on pump or something else?

Thank you for your help.