I just had a similar problem like that. Here's what I did.....from the outside, pull the wire off the oil pressure sensor and try to start it, then see if it stays running. I my case, it did. I reconnected the wire and it stopped. I had changed the oil and filter not more than a month ago and all was correct, the oil was not diluted either. I tapped the sensor with a wrench, connected the wire and all is fine. Hope that helps. Let us know.
Tim ,Retired Police Lt. 2002 Winnebago Adventurer+16' Trailer
Harley Road King and Heritage Classic+,Trik-L-start,Hughes Autoformer. Blue Tick Coon hound