C8 Acceleration During Braking

[2vettes]

On rare occasions my 1999 C5 used to feel like it was about to accelerate as I braked. This was a bit worrying if in a traffic queue or a stop line. I would rapidly throw it into neutral and the throttle would die down again.
I used to put this down to having big feet and maybe catching the edge of the accelerator pedal while braking but I'm not convinced of that.

Yesterday after a fairly long journey I felt something similar on my 2023 C8 and a couple of times I took the same action, switching into neutral quickly, after which it braked hard to a stop but then was okay. I need to get out and try to see it it happens again.
Is this just big feet (I doubt it as the pedals are quite a bit apart) or an issue in the mechanics/electronics that anyone else recognises?

Alex.

 

[Chevrolet]

I'd ask on here if you are on Facebook:

C8 Corvette owners UK | Facebook

www.facebook.com

 

[2vettes]

I'd ask on here if you are on Facebook:

C8 Corvette owners UK | Facebook

www.facebook.com

Thanks but no I don't use FB

 

[Roscobbc]

That symptom is reminiscent of cars I've driving that have had a turbo conversion where perhaps you might accelerate in traffic then let-off the gas ready for a corrective brake application.......yet the boost hasn't 'bled-off' quick enough and the car momentarily continues accelerating.....
Is your issue a fueling problem?

 

[2vettes]

Is your issue a fueling problem?

Interesting suggestion. I will pay more attention to what I'm doing just before it happens and try to find a pattern.
Yesterday it was when coasting down from speed and then applying the brake to stop at a junction, I felt the car pulling me and fighting the braking. Hence a bit concerning.

 

[teamzr1]

On rare occasions my 1999 C5 used to feel like it was about to accelerate as I braked. This was a bit worrying if in a traffic queue or a stop line. I would rapidly throw it into neutral and the throttle would die down again.
I used to put this down to having big feet and maybe catching the edge of the accelerator pedal while braking but I'm not convinced of that.

Alex.

As to the C5 you did not state which tranny it has

Sound like the throttlebody could be sticking or a small air leak
Assure the airfilter, MAF and the throttlebody are clean and closely check there is no air leak from the filter to TB, the airbridge couplers are good and also tight.

Best is using a OBD2 scanner would allow seeing what happens where the surge happens

Could at least is some tests, at idle
See if happens more when engine is cold, A/C on and off and when in park, gear or neutral and watch the RPMs and see if returns to idle smoothly to about 700 RPMs or a bit higher if manual tranny

Make sure the PCV valve that when you shake it that it rattles easily