I have a 2000 Olds Bravada AWD 4.3L v6.
I bought it from some guy that kept driving it when the lower intake manifold gasket blew and eventually blew both head gaskets. The truck would still barely run, but it had a tick so I decided to replace it with a junkyard motor with much lower miles. The new motor came out of a 2000 chevy blazer that was hit in the rear. I put the new motor in and it would only start if I sprayed gas down the throttle body. It has good fuel pressure at 60 psi. The injectors are not getting signal. They get a positive 12 volts but no ground. I understand these are ground pulse switches. The security light is not on when the ignition is in the on position. I switched the cam and crank sensor from the old motor and nothing changed. Has anyone had this problem before? Can someone get me a pinout diagram for the fuel injector harness. It has the spider injection. Could it be from the computer not recognizing the key? I made sure all the body grounds were attached and all the harness is plugged in. The car ran before i swapped the new motor in. I checked all the fuses under the hood and they were all good.

Thanks in advance
-Ben