GT2 revving itself - issue

[Tsunami Sting]

2019 Kia Stinger GT2 AWD. Engine revving itself sometimes. I put it in drive this morning and it about floored itself forward. Definitely not feeling safe to drive.

Also engine start/stop, auto-hold, and cruise control effected as well; from what I imagine--it's because it's constantly giving it a little throttle while driving but not when pushing on the brake. Cruise control is not on when this happens.

Checked vacuum lines from the brake booster as well as a few others, can't seem to find any leak. Also unplugged battery for 30 mins, then tried the ETB restart sequence to see if it'd help to relearn. Nothing. It'll rev up to the limiter at 5k for a little, then drop down to 3k and hold.

This doesn't happen every time it's driven.. but it's been happening more and more recently. And Kia is a month out on their service appointments! Awesome! Haha

I bought the car CPO with intakes. It has a catback and denso plugs for about 10k-15k miles now, not running JB4 currently. No check engine light or codes.

Any ideas why this would happen?

Revving itself:

Overly high cold start:

 

[Snowwhite]

floor mat pressing pedal?

 

[NS_Stinger]

Does it have a throttle tuner? You can tell pretty easily by looking behind the gas pedal if you see an aftermarket harness plugged in and leading somewhere.

 

[Tsunami Sting]

floor mat pressing pedal?

It’s not. It has the OEM floor mats that have the peg that keeps it in place

Does it have a throttle tuner? You can tell pretty easily by looking behind the gas pedal if you see an aftermarket harness plugged in and leading somewhere.

It came with a WindBooster. I’ll unplug it. But would that cause it to rev itself though?

 

[bfglitch]

It came with a WindBooster. I’ll unplug it. But would that cause it to rev itself though?

It's a device that can alter your throttle/gas pedal, so yeah it possibly could be a problem.

 

[Snowwhite]

It's a device that can alter your throttle/gas pedal, so yeah it possibly could be a problem.

this is the most likely culprit. next would be something stuck in the throttle body keeping it from closing, but I think that would throw a CEL.

 

[Tsunami Sting]

It's a device that can alter your throttle/gas pedal, so yeah it possibly could be a problem.

this is the most likely culprit. next would be something stuck in the throttle body keeping it from closing, but I think that would throw a CEL.

Thank you guys for the responses. I unplugged the WindBooster and unplugged the battery to let itself reset.

I’ll post an update after I put some miles on it because this issue seems to happen somewhat randomly at times; it isn’t consistent.

 

[NS_Stinger]

It’s not. It has the OEM floor mats that have the peg that keeps it in place


It came with a WindBooster. I’ll unplug it. But would that cause it to rev itself though?

Whoop whoop 100% its going to be that Windbooster. Chances are the windbooster got damaged and is malfunctioning.

 

[ChaneRZ]

That Windbooster is done.

 

[Tsunami Sting]

Whoop whoop 100% its going to be that Windbooster. Chances are the windbooster got damaged and is malfunctioning.

That Windbooster is done.

I really hope it’s the windbooster! Such a weird issue!!

 

[bfglitch]

I really hope it’s the windbooster! Such a weird issue!!

So was it the Windbooster?

 

[Tsunami Sting]

So was it the Windbooster?

It seems to have been. I’ve gone probably a couple hundred miles so far and everything has been running normally!

If anything changes I’ll send another update.

Thanks for the responses everyone

 

[Brotherspoon]

Years late but just want to comment that I had weird idle and runaway issues with my windbooster GT on my '18 GT Limited. It is a culprit for this issue for sure. I reinstalled it on my '23 3.3T and it works fine, although I have modified it for a full relay-based bypass back to stock with a toggle switch so I can make-safe in any malfunction event.