I do not have a wiring diagram for a 6F with 4Y.
But I do have a diagram for an early 7F (pre-TWC).
The fuel cut relay gets its ground from what Toyota calls a "rev switch". My interpretation of rev switch is that it is a switch that closes when it senses engine rotation by a signal generated in the igniter unit inside the distributor. Essentially, a tach signal circuit that tells the rev switch that the engine is running (or at least cranking) and thus it is OK to close the fuel relay and operate the fuel solenoid. This way, if the engine quits running for any reason, the fuel solenoid is not able to let fuel escape that could pass through the dead engine and, well you know why that is bad.
Check the tach signal wire in the small, two wire shielded coaxial cable that serves the distributor. If the tach signal wire is broken, you can have stalling or no start.
If you find a broken tach wire inside the coax cable, and you decide to splice repair it, make sure you DO NOT get any strands of the bare shielding wires included in your splice.
If the tach wire has continuity to the grounded shielding wire, you will not have spark or fuel.