The FP relay needs a signal to trigger the contacts to the pump...this same signal is for ignition.

You know the pumps run cuz you jumpered the load side of the relay...but it is the coil of the relay that is looking for a signal. That sig triggers the FP relay LOAD side.

That is why I mentioned way back to check fuse #6.
That is feed for both ign and FP relay coil side.

The chain is Ign sw/fuse 6/ ovp/ ecu/ FP relay

I am still awaiting a responce to my post of fuse 6.
But I don't see one.
So maybe you feel that post was not important in the diagnosis .
Point being...no power from fuse 6 equates to no spark/ no Fuel pressure.

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A Dalton

Apologies - yes fuse 6 was changed when you mentioned it.

If anyone can point me in a direction to test something then I would be most grateful.

W:
Did you ever find the cause of this problem? This sounds like a challenging one and I'm curious if you ever nailed it down.
Eric