Odd issue with acceleration

reldas

I did a bit of search but couldn't find anything about this issue if you could call it an issue.

I have a 7AT 2009 370z and it runs perfectly fine don't get me wrong but say im at a traffic light if i push hard on the brake pedal release it and then accelerate i speed up really quickly but if i light hold the brake pedal (just enough to stop the car) i will accelerate normally. It quite a noticeable difference. Anyone have heard of this before?

SouthArk370Z

The ECM limits power when the brake pedal is pressed.

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BuckeyeZ

Yep. Safety feature to avoid unintended acceleration.

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reldas

no its not that, im not sure if i explained it correctly. Once i release the brake pedal from press it down HARD i get crazy acceleration but if i release the brake pedal after just softly holding it in acceleration is normal. I'm NOT accelerating when the brake is held in.

Lukcas61

Well, your not supposed to accelerate when the brakes are pushed in? That pretty much defeats the purpose of the brakes no?

SouthArk370Z

So if you hold the brake pedal down with "normal" force, release the brake fully, and press the gas pedal, you get "normal" acceleration. If you mash the brake pedal hard, release the brake fully, and press the gas pedal, you get "crazy" acceleration. Since the car has no idea how hard you are pressing the brake pedal, that doesn't make sense to me.

It may be a faulty/misaligned brake switch, but I wouldn't bet any money on it.

Good luck figuring it out.

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reldas

Thanks, your the only one that actually understood what i meant. Its such a weird problem but i'll just ignore it.

SouthArk370Z

How well do you know your Z and cars in general? It it possible that what you are calling normal is actually limited output and normal output is what you are calling crazy?

The brake pedal may return to a slightly "higher" position after being released from hard braking. If the switch is not properly aligned, it may not be actuating when the pedal returns to a "lower" position after soft braking.

Edit: Oh yeah! Check the level in your brake reservoir. If the level is the slightest bit low it can cause traction control to kick in.

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DOOMMONKEY777

You need a retune, basically the brake has nothing to do with it, yes the Z has a saifety engine off if you hold brake and gas, but thats not what is happening here.

I think what is going on here is the estimated touqe in the ECU software setting, and vdc working together to remove wheel spin by controling engine output.

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reldas

I know my zed pretty well. I am going to take it in and get the ECUtek tune checked ( had it for over a year though) and get a full fluid flush just in case or just go supercharged and that should fix the issue haha.