The cold-start injector only fires when the temp is below 60F or so.
So, be sure it's cool enough for the computer to turn it on before condemming it. To make it fire manually, just unplug the connector and hit it with 12V. Poor initial start above 60F can be traced to several things, but injectors are always the first suspect. If you turn the key on for a few seconds, then off 3 times before starting, and it improves, check for retained system pressure, the accumulator or check valve leaking, or a clogged filter (unlikely).

DG