I disabled my OMP and am running premix now. The problem is, that on a series 5 you need to leave the OMP functional to make the ECU happy, but disable its oil pumping capabilities. So I removed the internals and left in the piece the little motor pushes against and the sensor. Well everything works fine untill I go above 6k rpms. It's like clockwork, at 6k the check engine light comes on and the car goes into limp home mode. The limp home is not as bad as I had thought it was going to be, but bad enough to make it obvious. I drove it around for about a half-hour with no trouble, then as soon as I decided to go over 6k it happens. So something goes down at that particular RPM with the OMP system. And I need to find a way around it. The OMP itself is a very simple pump with a overly complex electrical system. What confuses the hell out of me is that the only two things that are wired into the ECU are still intact. There is the little round black motor, the plate and rods that it pushes against, and the sensor the plate pushes against. So those three parts should be the only ones that need to stay functional (as far as I can tell). I am open to even the stangest ideas. Riding around under 6k is for domestics.

 

I've never taken the OMP apart or anything and my car is an 86 anyway so...
How about this:
The mechanics begin to float at high RPMs without the oil pressure that's normally in the pump forcing the pump to return to "normal" position. This causes the sensor to think the pump has stopped working and hit's the killjoy button.

Just a theory
Cory