Fuel issue

Alexws40 · Post by **Alexws40** » 25 Aug 2020, 21:24

Hello,
My s40 started to hesitate as if running on 3 cylinders when put in gear and a round yellow light within the gas gage blinks and disappears but can not find, anywhere, what this indicator is. Initially, it came once and disappeared not it does it all the time. Does anyone knows? Thanks

Post by **RickHaleParker** » 25 Aug 2020, 22:01

The yellow light on the gas gauge is the Low fuel level warning. For some reason it thinks you are low on fuel ... are you?

Post by **volvolugnut** » 26 Aug 2020, 11:07

If not low on fuel, maybe you have a pinched fuel line or plugged fuel filter restricting fuel rate.
Volvolugnut

Alexws40 · Post by **Alexws40** » 26 Aug 2020, 11:24

Thanks
I do have a P0456; gas evaporation code. Looked for kinks, vacuum leaks as it only shows symptoms when put in gear but and found nothing. Will replace the fuel filter but can't imagine it being the cause as if it were, it would malfunction even while idle. Frustrating for sure.

Post by **alschnertz** » 26 Aug 2020, 18:36

I'd check the fuel pressure before randomly replacing parts.
Should be around 44 psi.

Alexws40 · Post by **Alexws40** » 26 Aug 2020, 21:26

Great idea. Thanks. I will do that.

Post by **RickHaleParker** » 26 Aug 2020, 23:32

Alexws40 wrote: ↑26 Aug 2020, 11:24 I do have a P0456; gas evaporation code.

It failing the EVAP leak test. The most common source is the Fuel Cap is not tight or the Fuel Cap Seal is defective.

Possible source

Fuel tank filler cap missing:
The fuel tank filler cap is missing or not tightened, there is a large leak in the fuel tank, fuel filler pipe, fuel tank filler cap, EVAP canister, canister purge (CP) valve, or in the hoses between these components.

Major leak:

There is leak larger than 1 mm in the fuel tank, fuel filler pipe, fuel tank filler cap, EVAP canister, canister purge (CP) valve, or in the hoses between these components. Or a bunch of leaks that add up to 1mm or larger.

Minor leak:

There is leak larger than 0.5 mm but smaller than 1 mm in the fuel tank, fuel filler pipe, fuel tank filler cap, EVAP canister, canister purge (CP) valve, or in the hoses between these components. Or a bunch of leaks that add up to .5 - 0.99mm.

Alexws40 · Post by **Alexws40** » 27 Aug 2020, 08:46

Great information. THANK YOU!