Re: No Oil pressure after changing oil.
This - I've never heard of an automotive/marine oil pump losing prime. I always drain the boat and cars overnight or longer - no patience to sit and wait for it to trickle out.
The advice here is sound.
1) different oil filter
2) check the wiring/ground to your dash
I would normally agree but I had it happen on my Jeep ('87 4.0 XJ). It was a very worn motor that I was refreshing the bottom end on.
It was apart in the driveway for a couple of weeks. I went to start it after the refresh and got no oil pressure. I shut it down and tried to get a prime spinning the oil pump with a drill and, nothing. Tried and tried and tried to get a prime and couldn't.
I pulled the pan off and put a new oil pump in it, I got a prime right away and always had good oil pressure after that.