Re: hard start

From your description of hard starting after sitting (1 day, 2 days?), the fault is likely to be failure of the various check valves and pressure regulator to hold residual fuel pressure in the system. Test this by cycling the fuel pumps 2-3 times without cranking the engine. Key ON (not start), listen for fuel pumps. When pumps stop (about 2 seconds), key OFF, and back ON again. Cycling the pumps will build system fuel pressure. Now try starting.

If this is successful, only a few components of the fuel supply system will need to be addressed; the air flow sensor and fuel distributor are parts of the fuel metering system.