Hi All,
I have driven 240s for 10 years, and this is the first time I am stumped!

My 90, 240, US edition died out the other night. I have swapped out the relay and computers with several spares with no luck.

Here are the symptoms:
Car cranks, but no fuel pumps or relays kick in. Car starts and runs great on ether or when fuse 4 is hot wired. Only problem there is the pump runs full speed and never stops, so I can't drive too long like that.
No power to fuse 4, which is controled by the relay.
Fuse 6 is okay.
The relay does not click, but does read positive on the red and 2 orange wires.
The blue and green wire (pin 20 to the pcm), which controls the pump circuit, does activate the relay and pumps when grounded out.
No OBD 2 codes, both ports show 1-1-1
All fuses,including the one under the hood, okay

but it can't be the relay because I have tried 3 spares! Even looked up the right part number, to make sure.

So my question is: what next? I know cars pretty well, but can't figure out how the PCM knows to regulate the pumps.

I could also check the pcm connections and relay connections for damage, but this was very sudden, and has never stalled.

Electrical, overlooked component, 2 bad pcms?

Thoughts?
Bill
daimlerboy@aol.com