Q:

what should be the voltage of the wires going to the MAP sensor on the PLUG side?

what should be the voltage of the MAP wires leading into the ECU?
D17 & D19 slot
http://technet.ff-squad.com/wiring.obd1.htm

 

The reference should be 5volts. The signal will depend on manifold vacuum and elevation.

 

D19 should be 5 volts
You could bench test is with a vacume pump. And watch the voltage sweep.
With anolog meter or digital meter.

 

i just decided to run the 3 wires from map sensor to the ECU....
i figured there must of been a short somewhere.

NO more code 3 BUT car does have slight backfire at idel.... just not when you rev it.
Still running rich.

I'm going to try new ecu