you definitely wouldn't want it to do that just at key on without warning and at zero throttle, that would be a mistake.

remember with a TBI engine your injectors are before the throttle plate, so unless the engine is drawing vacuum or the plates are open, you're just spraying atomized fuel at a brick wall which will just fill your engine bay with fuel fumes.

you just need to get used to the fact that you need to turn over a TBI engine a half dozen times for it to start sometimes even when it's properly tuned.

i've seen a hack for TBI where hitting full throttle will give you a shot of fuel without the engine running, simulating what the accelerator pump on a carb does when you pump the gas). it was a long time ago. this at least squirts the fuel into the manifold. is that what you're talking about ?