Working on fixing the rest of the wiring for the engine for the 12V cummins conversion. I've had really good luck using alldatadiy.com, but still have some problems, mainly in determining what causes the pcm to energize or ground some wires...

I'm starving for fuel at the injection pump, and until I can upgrade to a FASS or an AirDog, I'd like to run both the cummins pump and the in-tank pump in series to keep my pressure high. I'd like to wire them together, for simplicity, and to keep the engine compartment looking clean



I can't figure out what causes the PCM to ground the wire for the fuel pump relay in the diagram above (pin 80, the LB/O wire). I need to bypass this so that I can get both pumps to work whenever the engine is turning or running, but not when the ignition is just key on but not running.

Can I just run this off of an oil pressure switch?



Pretty much the same question on this diagram, which feeds off the first one:
Do I need to have the fuel pump resistor for the pump to work, or can I just ground out the fuel pump to have it run at full pressure? I know factory the PCM controls the fuel pressure based on engine needs, but since its not reading my engine needs, it doesn't know how much fuel to supply...

I've managed to get 95% of the wiring the way I want it, this one is just puzzling me a little bit, and I don't want to start cutting without knowing what feeds the

 

I know the pictures are kinda hard to read, I've got clearer versions I can email if someone is good with their electronics and needs a better view...

 

Nobody can point me in the right direction on this?