P0171 code and stalles at stop

[zell66]

Recently replaced fuel pump and a section of fuel line. (work complete 2 months ago and put on 2000 miles) Yesterday check engine light came on and it gave me the code above and stalled every time I came to a complete stop.This is a 5.3 l non flex motor.

Any ideas or direction I can go to fix this vehicle. Thank s!!

 

[HiHoeSilver]

Recently replaced fuel pump and a section of fuel line. (work complete 2 months ago and put on 2000 miles) Yesterday check engine light came on and it gave me the code above and stalled every time I came to a complete stop.This is a 5.3 l non flex motor.

Any ideas or direction I can go to fix this vehicle. Thank s!!

Bank 1 lean code.

Check for vacuum leaks.
Check fuel pressure at the rail.

Do you have a scanner that you can see/ graph live or freeze frame data?

 

[zell66]

Well he is a conundrum....on a hunch filled tank and within 2 to 3 start and stop of engine, check engine light goes off and truck does not die at a stop. Could it be the fuel is sloshing around and fuel pump lost prime????

 

[HiHoeSilver]

Well he is a conundrum....on a hunch filled tank and within 2 to 3 start and stop of engine, check engine light goes off and truck does not die at a stop. Could it be the fuel is sloshing around and fuel pump lost prime????

How much gas did it take? Could have been bad gas or high ethanol content.

 

[swathdiver]

Recently replaced fuel pump and a section of fuel line. (work complete 2 months ago and put on 2000 miles) Yesterday check engine light came on and it gave me the code above and stalled every time I came to a complete stop.This is a 5.3 l non flex motor.

Any ideas or direction I can go to fix this vehicle. Thank s!!

Did you replace the pump itself or the entire assembly?

 

[zell66]

How much gas did it take? Could have been bad gas or high ethanol content.

it seemed to stall at just under a 1/4 tank. we use regular unleaded.

 

[zell66]

Did you replace the pump itself or the entire assembly?

I replaced the entire fuel pump assembly.

 

[HiHoeSilver]

it seemed to stall at just under a 1/4 tank. we use regular unleaded.

If it's not doing it now, I would run a couple tanks of premium through it and some fuel system cleaner. Techron or Kreen preferred.

 

[swathdiver]

Check intake gaskets and fuel trims next on that side.

 

[zell66]

A mechanic buddy of mine suggested it was the throttle body?