If it only takes a long time to start after it has been sitting around, like overnight, that's a leaky anti-drainback valve letting the fuel drain down out of the fuel rail that connects to the fuel injectors and back into the gas tank. The long start time is the amount of time it takes the fuel pump to get fuel back up to the fuel rail on top of the engine and thus to the fuel injectors.
The anti-drainback valve is located inside the fuel pressure regulator that is positioned on top of the fuel pump. The fuel pressure regulator with that valve inside can be purchased separately and can be found either at the dealer (usually) and often on eBay for less $$$. You do have to drop the fuel tank to replace it but that's not a big job.