96 Tacoma fuel pump

Guys looking for suggestions. I bought a 1996 Tacoma and the previous owner put a motor in it. He can’t get the fuel pump to kick on any suggestions before I tackle this??? Thanks

 

First thing is to understand that the pump does not come on with just the key in the on/ign position.
There are a fair number of threads on trouble shooting.

Fuel pump control, theory of operation.
Note 4cyls use the cam sensor, 6s use the crank sensor. Pretty much the same through the years but relay location/type varies. Also note that the "EFI" and "Circuit Opening Relay" are in series.
The diagram can be a little confusing in that both the "start" and cam/crank sensor will allow the ECM to run the pump separately. The "start" signal gets things going quick and the crank/cam signal maintains operation when the key is released.

 

Ok this will help. So potentially the ecm could be bad?

 

Could be as simple as a bent or loose pin.

Fuse loose in the socket corroded connections if things sat for some time.

Crushed wires pulling or installing the engine.

I am guessing the sensors and engine harness were swapped .

Any idea why the engine was swapped ??

Have you checked the fuel pump harness is plugged in??

Fuel pump does work??

 

I am actually getting the truck this Friday. I was just trying to get some ideas before hand. More to come. Thanks for the help so far.