fuel pump problems?

[crosby]

I have an 87 V20 pickup, just got finished sticking an engine in it from an 87 Jimmy, and it won't start. When I switch tanks, you can a whining sound, like a solenoid or something. Could that be something that switches tanks only? Looking into the throttle body, I don't see any gas at all on the intake floor. There is some dirt or rust in there, which I should probably vacuum out somehow... Any idea what harness should be connecting to power the fule pumps, and where it is supposed to connect? Thanks for your help!