'87 5KTQ electrical questions

[MHLIGGINS@aol.com]

    The black quat is still down. Symptoms are that the
car will not start. And when the switch is turned on the 
dash gauge shows 2.1 bar of pressure. When the fuel pump
relay is removed it still shows 2.1, when the ECU is 
pulled it shows 0.0 bar.
     When I have the intake manifold ground in place
I show +12v when I connect ECU #19 to the battery 
through a DMM. When that ground is disconnected I show
+5v with the same connection.
     I still think it's a wiring problem, but I'm not
sure if I have one grounded that shouldn't be or if 
there is a ground that's not good. Any ideas? Any place
in the wiring harness I should look?
     Would love to get this one back on the road.

     Thanks.
     --ml