sudden jerk in second

[jksgoh]

I've noticed a funny jerk which has happened a few times when im second gear and am wondering if anyone else has experienced this.
It's only happened 4-5 times tops in the 1 year i've had the car so im not particularly worried about it, but just interested to see if it happens to anyone else.
Ok so what actually happens: From a stand still starting in 1st then changing to 2nd, once i've fully released the clutch while in 2nd and step on the gas a little the car will suddenly jerk and then accelerate as normal. It feels almost exactly the same as when you release the clutch up too quickly and you get a bit of a jerk, only in this case it seems to happen say 1/2 sec after i've fully released the clutch.

anyone know what this could be? possibly related to the CDV???

[Lester]

It sounds like DSC cutting the engine power. Try the same scenario with DSC/DTC turned off.

[Evice]

cluth, gear or something is slipping?

[Mega Man]

It's cat related:



Have you asked your dealer?

[Alow]

CDV? that would be my guess.

[supraking]

First thing that came to my mind was DSC as well. You might be hitting a bump or a slippery section that is causing DSC to reduce power, and then it will re-engage resulting in that "jerk" forward you feel. It's hardly ever happening so try to replicate it first (i.e. test in the same area it's happened in the past) and try with DSC on/off.

To turn off DSC: Hold down the DTC button in the center console for 5 seconds. The warning light (triangle with exclamation point) will come on. To turn back on, press the DTC button once.

[frimmelnojerz]

all that torquez.

[jksgoh]

hi guys, thanks for the replies.
megaman: i haven't asked the dealer yet, as its only rarely happened and i havent even gone in for my first service yet.
as for DSC, for some reason i didnt think of that.... maybe it is... but i must say that i have had dsc go off before on and it has felt different... but i guess its still a good possibility. As for trying to replicate, its always been on a different stretch of road, but its never been wet either, and as it rarely happens its difficult to replicate.
guess i wont bother too much about it and just mention it to the dealer when its time for service.

[Jaguar66]

!

[Sansnoetic]

not sure if this is the same thing, but sometimes i get a small jerking after releasing the clutch and then pressing the gas a little. i always thought it was CDV or something. it's almost like the clutch is sticking or something and not fully engaging...

[RPM90]

Originally Posted by jksgoh

I've noticed a funny jerk which has happened a few times when im second gear and am wondering if anyone else has experienced this.
It's only happened 4-5 times tops in the 1 year i've had the car so im not particularly worried about it, but just interested to see if it happens to anyone else.
Ok so what actually happens: From a stand still starting in 1st then changing to 2nd, once i've fully released the clutch while in 2nd and step on the gas a little the car will suddenly jerk and then accelerate as normal. It feels almost exactly the same as when you release the clutch up too quickly and you get a bit of a jerk, only in this case it seems to happen say 1/2 sec after i've fully released the clutch.

anyone know what this could be? possibly related to the CDV???

I know what you mean.
I think it's the drive by wire throttle. Sometimes, for what ever reason, it responds just a tick slower than we like and what we ask for with the throttle. I've been drivng manuals for years, and with the advent of drive by wire throttle this has become more common.
Sometimes these things just don'f feel as linear ad "analog" cable throttle control.

You would think that being digital would make it just as smooth every time, because you think, when the throttle pedal is at this point it means the throttle plate should open the same amount everytime.
But, we've all experienced these little electronic "glitches" where that's just not happening. Sort of like the auto up on the window works pretty much the same every time, except once in a while it goes up and then stops for no good reason and comes back down.

I'd like to see adjustable throttle tip in as well as adjustable throttle trim.
My RC car remotes let me adjust the throttle control to a much greater degree, well, the car doesn't have any adjustments.
I can adjust my RC throttle to open faster or slower depending on how much throttle I give. I can also adjust how much throttle opening I get given the amount of control I put in. For example, I can move the throttle 10% but get 20% movement in the throttle. Also, I can adjust so that the first 50% of remote throttle movement results in just 25% percent actual throttle opening at the carb, and then the other 50% of remote opening controls the other 75% of actual throttle opening.

Yeah, it can be too much adjustment for most drivers. But for enthusiasts, why not put that option in there and we can just swith it on or off if we want to use it.

The power software tuners have now come out with updates to fix the throttle response "lag" where it takes the actual throttle a second of two to actually respond to your pedal input. IOW, it's not linear at all.
With the updated software, the actual throttle opening is now nearly in time with your pedal throttle movement, thus it's more instant and right there.

So, I think part of the feel you, and I, have gotten, is that lag. Sometimes it's more pronounced. It might not be a glitch at all. It could just be that sometimes we "feel" we put the right amount of input but we didn't.
By having this long lag, we're not getting instant feedback to what we're doing, so sometimes we adjust the throttle to get the reponse but the computer is still working on the input we gave it a second or two ago, so you can see how sometimes that delay can result in "too little" then "too much" then "too little" throttle, and we feel it as a jerk forward, then back, then forward, very quickly.