Fuel pressure Silverado 1500 2011

[Fernando Giral]

Hello I have a Silverado 2011 5.3L flex fuel

 

it seems that my fuel pressure is low I went to AutoZone to get the scanner it reads:

-P0174 System to lean Bank 2

-P0171 System to lean bank 1
-P0174 System to lean bank 2

-P0171 System to lean bank 1

-P0174 System to lean bank 2

-P0171 System to lean Bank 1

 

it seems the best fix was changing the fuel pump.

i changed the fuel pump yesterday but it struggles to turn on after a few hours

after it has been on for a few minutes it will turn on normally, there seems to be no way to check the pressure on this truck I checked for any leaks in the fuel lines can any one help me?

[CamGTP]

There is a fuel pressure test port of the fuel rail under the beauty cover. You can also check fuel pressure with a scan tool as flex fuel trucks have a fuel pump control module.

 

Intake gasket leaks, throttle body gasket leaks and leaks in the air tube from the MAF to the throttle body can all cause lean codes as well.

[Fernando Giral]

Thank you very much I will take a look at all these

[Ianf]

You also need to scan and get an ethanol percentage reading first. If the % is way off i.e. 45% when your only running a known 15%, then you have a vacuum leak and have not been following proper refueling procedures. Make sure the vacuum test port on the right side valve cover is not leaking (it is a tab that breaks off and needs to be capped after the test). The hard start is usually the throttle position sensor or fuel pressure.