2012 2LS doesn't want to start after getting filled up with Gas... Runs rough after

[fbodyauto]

Hey everyone,

I hope you all had a great Thanksgiving! I just wanted to drop a question here based on a recent issue with my Camaro and see if anyone else has had it or if you have a solution.

First off, I have a 2012 2LS with the LFX. Car is unmodded with just over 50xxx on it. Since owning this car new, I have had almost zero issues with it.

My issue, although it seems minor, happens when I fill the car up with a full tank of gas. It all started a few weeks ago when I went to fill up. I always fill up at a decent place (Shell usually) with 87. I also never let my car run super low, usually have just under a quarter left when I fill up. OK, back to it. This time I go, fill up my car, and when I go to start it up it turns over numerous times, like a starter issue, and I had to pump the gas a few times to get it running. Once running the rpms kept going up and down, like 500 to 1000, and it felt like the car would die. This would only happen when at a red light or stop sign for the first couple minutes after filling up. After driving for a mile or so, car was fine and every other start was fine through the entire fuel cycle.

Now, I go to fill up again. I pick a different gas station and the same thing happens! I drive around a mile and sure enough it is gone. Now I am just confused.

Now, halfway through the tank in my 2nd fill up with the issue I get an engine light (which may or may not be related) that reads P0496 – Evaporative System High Purge Flow CONFIRMED. I cleared the light to see if it would come back on and it did a couple days later.

Now besides the light, which I am unsure the exact cause, I have filled up 2 more times and both times again, the same issue.

So that’s it… I wish I knew more but that is why I am here. Luckily my car runs and drives fine with the exception of just after the fill up. I always make sure the cap is closed and I have always used the fuel injector cleaner from Lucas. Please let me know what you think this could be?

[Racin J]

Are you tryin to put more gas in after the first click-off at the pump? People dont get that tryin to squeeeze in every drop of gas will enter into the evap system and cause drive ability problems..just a first thought

[fbodyauto]

Originally Posted by Racin J

Are you tryin to put more gas in after the first click-off at the pump? People dont get that tryin to squeeeze in every drop of gas will enter into the evap system and cause drive ability problems..just a first thought

I read that on different forums before posting and no, I haven't. There has been times I have done this but in the past and not recently at all...

[idealer]

Fuel pump may be going bad

[Night trained]

Bad ignition switch

[b4cz28]

My truck does this and it's a 2011. Only after I fill up and now if I just put in 3/4 of a tank it does not do it.

[clashley1976]

How well does your fuel cap seal? Does it still "click" when you tighten it? My F150 gets weird "evap" CEL codes when the fuel cap is not tightly closed (actually had a fuel cap wear out to where it wouldn't "click" anymore, and then it would pop codes within 50 miles or so of a fill up).

[JerTM]

The dtc you provided indicates a bad purge valve which will cause the issue you have described. The evap purge solenoid is sticking open and allowing fuel vapor to enter the engine through the vacuum line basically causing a rich condition. Hard to start, acting like its flooded are both symptoms. It shows up when you fill up because the evap line on top of the tank is more likely to have fuel in it right after a fuel up. Replace the purge valve, its the one near the engine and easily replaced.

[fbodyauto]

Thanks everyone for your input. I think I'm going to see if JerTM's method works. I will be trying it soon, will do some reading on the replacement.

[Angrybird 12]

Originally Posted by JerTM

The dtc you provided indicates a bad purge valve which will cause the issue you have described. The evap purge solenoid is sticking open and allowing fuel vapor to enter the engine through the vacuum line basically causing a rich condition. Hard to start, acting like its flooded are both symptoms. It shows up when you fill up because the evap line on top of the tank is more likely to have fuel in it right after a fuel up. Replace the purge valve, its the one near the engine and easily replaced.

That would be my guess too, it's supposed to be checked every 45K miles according to the maintenance schedule in the owners manual. But who pays attention to those?? They are just written by a bunch of lawyers to cover GM's butt, Right?

[JerTM]

Fwiw I am a GM tech.

[fbodyauto]

Hey JerTM, I have been looking online but haven't found exactly what I need.

Would you by chance know the purge valve item number for lookup at a auto parts store and also, I know this is dumb, have a picture of where it is for me to see?

I am somewhat mechanical but have not idea what this would look like..

[motorhead]

You may want to check out this thread before you start buying some very expensive parts. I would check to make sure it isn't under warranty.

[Angrybird 12]

Originally Posted by fbodyauto

Hey JerTM, I have been looking online but haven't found exactly what I need.

Would you by chance know the purge valve item number for lookup at a auto parts store and also, I know this is dumb, have a picture of where it is for me to see?

I am somewhat mechanical but have not idea what this would look like..

I would think that could be covered under the emissions warranty if its bad. Check with your dealer to make sure.