Hesitating to Start

[justirv]

At the time I bought it off Amazon, but I stopped buying OEM parts from Amazon. I’m confident it’s not the fuel pump because this issue was occurring before I replaced it. The fuel pressure specs are as follows before I replaced the fuel pump.

46 psi when key was on but engine off.
42 psi with engine running
42 psi after engine was ofF

I agree with you on re: AMZ "oem" parts, I quit ordering those from them several years ago. Your fuel pressure sounds low to me, I do not recall actual spec (maybe 58psi?), with a bit of difference between gas and flex. Check the fuel pressure regulator on the rail? That bleeding off pressure could also affect your hard starts.

 

[Fless]

It would be helpful if there was some vehicle and drivetrain info in your signature. Not all are the same.

For fuel pressure, according to Haynes:
KOEO
Flex Fuel: 48-54 psi
Non-Flex: 55-62 psi

Either way the KOEO pressure is below the minimum. If it's a FF system has the inline fuel filter been changed?

 

[nonickatall]

These were the fuel pressure readings before I replace the fuel pump.

46 psi when key was on but engine off.
42 psi with engine running
42 psi after engine was off

Isn't that a little low? Should be between 55-62 PSI, so you should swap the fuel pressure regulator and fuel filter, if your Tahoe has one. Some of the cars have the fuel filter inside the fuel pump.