Hey guys I installed a fuel pressure gauge and it's reading really low numbers. I read the specs for the KOEO pressure is 35-45psi but I see anywhere between the high to low teens. This is after shutting the engine off right after. I have 30psi with the car at idle but I'm seeing 2 different specs for it 35-45psi or 30-40psi and I'm not sure which spec is correct. This pressure is possibly from a pump with over 250K on the car. Will need some input on this? The engine is running a bit rough but runs good cruising around though just need some input on anything that will help.