I'm familiar with older inline pumps (such as used on my 1979 2977cc B-engine) but unfortunately yours is quite different.
To tell you the truth, it has thrown me to see any INLINE PUMP at all sitting on a 15BFT engine (and even more so because my May 1995 FSM (RM464E) shows only the rotary pump)!
So....Maybe you need to bleed air from this mysterious inline pump ..... because mine certainly won't deliver any fuel at all if it has air inside it. (Mine has a bleed nipple for this very purpose.)
Where is your "feed pump"? (Mine is "a plunger-type pump" working off a cam inside my injection pump.)
And do you have a fuel-return line running back to your fuel tank?
And do you have a primer pump, and if so where is that located?
Sorry for all the questions .... But I need to understand more about your fuel system (so I can take more "stabs in the dark" while we await the arrival our resident injection pump expert)..
PS. In case you're not already aware ....All the pics I've posted so far don't relate to your particular engine. To find yours I really need to know the model & year of the Toyota from which it was extracted..