2002 accord LX 2.3L 237k miles (manufacturer date 07/02)
I have been using the diag tree posted below.

I have run an overlay
​​​​fuel pump relay pin 4 to ECU pin b1 and now have power (where it says "no" in pink in attachment page 3).

But do I run another one from ECU pin 9 also? If yes, to where?

 

Additional notes:

Previous owner replaced relay, it looks like twice (found some in footwell), as well as fuel pump

Green key light solid

Timing is also on (there was a new crank sensor in a box with belt so did that at same time as there was a fault for crank sensor that is no longer present)

 

Solid green light key, your immobilizer is saying that it will not allow you to start and run the engine. It does this by denying fuel and injector pulse.

 

Thank you for taking the time to try to help me
I thought flashing was an error? Mine is solid for a few seconds then goes off if I keep ignition in ON position

 

Okay, then if the key light goes off then the immobilizer is functioning properly and not stopping you from starting the engine.

When the key is first turned to the on position, the fuel pump will run for two seconds to prime the fuel rail with enough pressure to run the injectors.
The test you did is not valid if you took more than two second to measure the voltage to the fuel pump.
If you hold the key to crank position (or have a friend do it) then the voltage should be present at that pin.

Note: If there is no voltage then should check the wires.

 

Yes, when I turn on key I have power probe hooked to the yellow/black wire at pump, which I can both see and hear if it receives power

THats a really good point, so I retested continuity using t pins on the terminal pins for the power (yellow/black).

Going to try to find what grounds relay from ECU and see if that's the culprit.