Hey Scotty, my name's Avery and I'm from Florida, and I recently purchased a 2006 Nissan Sentra 1.8L Automatic with about 145,000 Miles on it. My issue with it is that when it first starts, it takes a few separate cranks to get it going. However if it is shut off and started back up in about 5-10 minutes, it cranks up just fine. Since I've bought the car I've replaced the: O2 sensor, MAF sensor, spark plugs, coil pack 4, Air filter, motor oil, battery, and I've also recently cleaned the fuel injectors. Only code that popped up was p0128 for thermostat function, and an unnumbered code that says initial start with no additional information, kind of stumped right now and i would appreciate it if you could help. Thank you Scotty!
Check your engine temperature sensor as well and probably replace them both.
Pressure test the fuel pump.
Your fuel pressure regulator may be bad. Those typically hold pressure in the FI system when the engine is off for faster starts. If it's not doing that the fuel pump has to work longer to build up sufficient fuel pressure for the engine to fire up.
