When you go to start it, flip the key to the "run" position. Let it sit there for 4-5 seconds without starting the engine. Turn it back off, and repeat that a few times. Doing that will make the fuel pump prime and pressurize the fuel lines. If you do that and it still takes 10+ seconds to start, you can very likely rule out the fuel pump.
I would get a scan tool that can read/watch live data, and take a look at the crankshaft potion sensor. If the computer doesn't know where the crank is at from a faulty or spotty sensor, it will just turn over the engine until it sees the crankshaft position so it knows when to time fuel/spark.
Lastly, check the MAP sensor on the intake. If it's going bad or has a loose connection, the computer won't know how to time the fuel and it can cause a starting delay/issue.