Ok, great. All of these codes and your starting problem all tie in together. The p0016 is cam/crank sensor misalignment, the p0344 is cam sensor signal intermittent, and the p0340 is cam sensor circuit. Your van has a sensor that tells the engine controller where the crankshaft position is, and one that does the same for the camshaft. It needs both of these signals to fire the coils and the injectors at the right time. You have one of 2 problems with your van. It could be a broken wire to the cam sensor, or it could be the sensor itself. Look over the wiring to the sensor, look for any rub throughs or places it could be pinched or broken. If you see nothing the best thing you could do is replace the cam sensor. Here is a picture of the sensor location. I advise you to use a Mopar sensor from a dealer. Aftermarket electrical parts have been known to not work right out of the box.
It is located on the top of the timing cover at the front of the rear cylinder head.