Fuel problem diagnosis

[creech_r]

I have two ae86 gt-s with the stock 16v in them that will start with starter fluid right into the intake manifold but won't draw fuel from the tank. I purchased a fuel pump from a salvage yard (supposedly running when pulled) and installed that into one of them with no change. I can unplug the fuel line that goes to the firewall side of the fuel rail and with enough suction get fuel from the tank. I'm just curious how one goes about troubleshooting the fuel system. I didn't find anything about the fuel system in the manual online. I imagine there's a set of relays that I would need to check along with power to the fuel pump. I've searched on this an a few other forums and couldn't quite find my problem or a conclusive way to check for problems.

Is this a typical problem? Also, where would I find the relays?

Thank you