1999 B3500, 5.9L, stalls unless PCV pulled out.

Hi, I'm new to the forum and look forward to your suggestions. I have a 1999 B3500 Van with a 5.9L, 125,000miles. When I run it from a cold start for maybe 20 miles it runs fine. After it sits for an hour or two and I start it up it stalls shortly after. One time all the dash gauges went crazy but eventually corrected itself. Reading the forum I have tried cleaning the throttle body and IAC and I replaced the PCV with a new non-MOPAR part. When this happens I found if I pull the PCV out (Still attached to the hose but free of the valve cover) it starts right up and runs fine. What's happening?