My 2000 Blazer LS has this weird problem.

Sometimes its a real pain to start, all it does it crank and you have to cycle the key and then it'll chug to life. Then you must let it sit and idle for 3-5 minutes or right off the bat it acts as if it's running out of fuel. (I.E bogs, chugs, acts like its gonna stall).


But once your driving it clears up and runs somewhat fine but it still acts as if it's running out of fuel, especially after makin a turn.

So I checked the fuel pressure and the KOEO pressure jumps to 50 and bleeds off to 45 and stays there.

KOER pressure is 51 and drops to 45 when a load is put on the engine.

It also has a Fuel Tank Pressure Sensor high and low code on. Now I haven't the slightest clue if the pressure sensor would cause drivability problem but I can't see 10 psi of fuel pressure causing the car to act like a complete jerk.

 

Your fuel pressure is too low. Anything below 60psi will cause driveability problems and hard starting. Below 50psi requires a shot of carb cleaner to get it started. Anything below 45psi the poppet nozzels will not squirt fuel. KOEO fuel pressure needs to be 60psi to 66psi while the pump is running. It must remain above 55psi for 3 to 5 minutes after the pump shuts off. Make sure the fuel filter is not clogged, then check fuel pump maximum output.

This link explains it: https://blazerforum.com/forum/showthread.php?t=45941