Hard start after fueling, Code P0496

[harbison]

'09 GMC Yukon XL 5.3 Gas (not flex) 234K
Recently had trouble starting after getting gas. Doesn't seem to matter if I get a full tank or a quarter of a tank. Also doesn't matter if I fill it slow or fast. Always has trouble starting after fueling. Once I did get a loose gas cap message.

Changed Vapor Canister Valve Solenoid (behind alternator). Old one was bad. You could blow through it so valve was stuck open. Problem persists. Even checked new valve to make sure it was closed and it was.

So what else could it be?

 

[kbuskill]

Need more info... can you describe "has trouble starting"???

Does it have any codes... CEL???

Does it act flooded or like it's starving for fuel?

If it acts flooded you could try holding the throttle to the floor while starting to try to clear it.

 

[PoorMansEscalade]

You probably have a bad vent valve on your Evap canister behind the tank. There is an updated harness for it also

 

[swathdiver]

'09 GMC Yukon XL 5.3 Gas (not flex) 234K

LY5 motor.

P0496 means your fuel tank is getting engine vacuum when its not supposed to. After 90 seconds of engine start the voltage on the fuel tank pressure sensor should be under 1.7 volts.

If it's more, replace the canister purge solenoid valve. Use ACDelco or GM OE ONLY.

 

[harbison]

Code is P0496 (in the title) I would say starved. You have to pump gas to get it to start. Idles erratically then smooths out and is fine.

 

[kbuskill]

Code is P0496 (in the title) I would say starved. You have to pump gas to get it to start. Idles erratically then smooths out and is fine.

I must have totally spaced out earlier... didn't even see the code posted in the title... lol

Sorry about that... carry on.