According to Giles from PDI the IP should be able to lift fuel from a jerry can sitting on the floor next to the engine. If it doesn't, providing the fuel supply line is good, the vane lift pump in the IP is malfunctioning or broken. I've researched that a bit because of my fueling issues. People have recommended soaking the vane pump with various solvents to get the potentially stuck vanes to come loose. Mine lifted OK so I never went there.
Compression check time then. Do you have the proper tools for it?