Wouldn't start until significant gas pedal pressing

[maxstead]

2015 LT

Has been running like a champ, and all of a sudden, hopped in today and it wouldn't start.

Checked what I would call normal items (coil pack plug, fuses, fuel pump sound, etc).

Last ditch effort I operated the pedal about 10x while cranking and it fired up. Spun up to 3600 rpm and idled there until I shut it off.

Tried to start again, no go. Pumped pedal 4-5x and away she went - same though 3200rpm or so until I shut it off.

Third attempt I didn't press gas as much and it started but ran rough - like misfiring, but smoothed out after 20 seconds or so. And it didn't rev high.....

Moved it in the yard in case it didn't start again, and then shut it off.

Tried to start it again and it was like nothing ever happened - drove 50 miles and all seems normal now.

Thoughts? Throttle position sensor?

Thanks in advance!

 

[Gigachad]

Did you end up figuring this out? I just had the exact same thing happen with my 2015

 

[maxstead]

Changed both the coils and the egr purge valve. One of them fixed it. Both cheap.

 

[Gigachad]

Changed both the coils and the egr purge valve. One of them fixed it. Both cheap.

Would you happen to have the part # for the purge valve?

 

[maxstead]

Just look in amazon for Chev Sonic purge valve 1.8

 

[Gigachad]

Changed both the coils and the egr purge valve. One of them fixed it. Both cheap.

I swapped out the purge valve last night, cleared up the hard start issue and rough idling upon startup. Thanks again for your help!

For reference to anyone who stumbles upon this post in the distant future experiencing similar problems, I took out the old valve and could blow right through it, meaning the valve had failed in the open position allowing gas fumes from the evap system to flood the intake, causing a rough or no start condition.