I'll try n keep this to the point..
after countless hours searching couple forums..

Current truck: 1991 Toyota 4x4 pickup 3.0L (3vz-e) manual tranny

purchased...
1996 ( I think)
5vz-fe auto tranny
with ecu and t case, MAS ,and 90% of harness..
Was removed over year ago by some body else n vehicle scrappped

i purchased new o2 sensors.

The harness was hacked off at drivers side valve cover..

wired in new o2 sensor pig tails. And evap pigtails..

now the harness has 5 plugs in total.
the ecu has 4 plug spots
only 3 of the 5 plugs fit into Ecu
used the r150 tranny from 3.0l
was told of trick to use auto tranny ecu wand run manual tranny
can't even get motor to (want to start)
Hear pic of plugs n ecu
my first guess is that i not getting power to Dcu.
I dont have any more info. Or access to doner vehicle
any help ell much appreciated...

or link to a already discussed forum page..

it your in the Medicine Hat , Alberta area, I'll gladely pay u for your time..

Right now I would go buy harness from ORS if it was readily available..

will try ANYTHING
need to b mobile by Sunday!! Gone over 5vzfe n 3.0l pinouts and can't finger stuff out.
frim the 5vzfe pin outs I did find..
tried to jump power. Still nothing

 

3-4 weeks isn't a bad lead time for the ORS harness to avoid headaches

 

The other two plugs for your ECU come from the body connectors. That's where your power, speed sensor, and several other things plug into the ECU. Unfortunately, those connectors were probably scrapped along with the rest of the car. You can buy them from a dealership or you can try to find them from the original manufacturer, which was probably Tyco or Amphenol.
If you haven't already figured it out, the driver's side connectors you're probably missing are the VPS sensor and VSV, the oil pressure sensor, and the crankshaft position sensor (IIRC). You can probably start the engine without these, but it is a REALLY bad idea to run an engine without a working oil pressure sensor.