Car buck/jerk near idle speed while in first gear.

[rml605]

Honda/Acuras take the cake for the worst manual cars at low speed. It's like im rolling through a parking lot on a galloping horse.

[Rope-Pusher]

It's like im circling around an office on a trotting horse.

Fickset

[havoktsx]

Honda/Acuras take the cake for the worst manual cars at low speed. It's like im rolling through a parking lot on a galloping horse.

aint this the truth! basically, in traffic, i'm slipping the clutch and coasting + no-gas launch all the way home... thankfully, its only about 30 min of bumper-to-bumper traffic at the worst... i have a feeling my clutch won't last as long as some of you who live in absolute barren straight and flat highway lands... that and the fact that i'm the 3rd owner of my car, well, who knows how the previous owners treated the car?

[ClutchFork]

I get a little bit of that first gear bucking at idle speed, but only when the engine is cold. Once warm it behaves nicely. What is your first gear ratio and final driver ratio? I don't think it is a problem of low gear so much as not low enough low gear. Try under same conditions, idling along in second and see if it bucks. Two things contribute to this bucking (I am hypothesizing here): 1) the lower the engine speed the more the less smooth they are and the more apparent the individual firings of each cylinder, and 2) the lower the road speed combined with low engine speed the more this lack of smoothness is brought out. Under point #2 if you have a lower overall ratio in first gear, then you won't be at idle, but at some higher rpm and so less prone to the bucking situation.

So to test my hypothesis, we need to see if it is worse in lower gears at idle than at higher gears at idle speed, of course not tromping it, which would induce a lug in the higher gears, thereby confounding the evaluation.

Or maybe I don't know what I am talking about!

Also, look here at this thread which was on same topic:
http://www.standardshift.com/forum/view ... 10&t=19106

[Rope-Pusher]

So to test my hypothesis,.......

[ClutchFork]

So to test my hypothesis,.......

Well at least you grant that my guess is "educated."

[havoktsx]

I get a little bit of that first gear bucking at idle speed, but only when the engine is cold. Once warm it behaves nicely. What is your first gear ratio and final driver ratio? I don't think it is a problem of low gear so much as not low enough low gear. Try under same conditions, idling along in second and see if it bucks. Two things contribute to this bucking (I am hypothesizing here): 1) the lower the engine speed the more the less smooth they are and the more apparent the individual firings of each cylinder, and 2) the lower the road speed combined with low engine speed the more this lack of smoothness is brought out. Under point #2 if you have a lower overall ratio in first gear, then you won't be at idle, but at some higher rpm and so less prone to the bucking situation.

So to test my hypothesis, we need to see if it is worse in lower gears at idle than at higher gears at idle speed, of course not tromping it, which would induce a lug in the higher gears, thereby confounding the evaluation.

Or maybe I don't know what I am talking about!

Also, look here at this thread which was on same topic:
http://www.standardshift.com/forum/view ... 10&t=19106

according to acura/honda, 1st gear - 3.27, 2nd gear - 1.88, final drive - 4.76...

i buck in 1st gear low rpm AND 2nd gear low rpm. only way not to buck is to clutch slip 1st or stay at a constant 1500 - 2000 rpm in 2nd. 3rd gear low rpm will also induce a mild buck; steady 1000+ rpm is smooth otherwise. idle is 750 rpm.

this is with the engine at full operating temperature.

[daleadbull]

I think the bucking near idle in 1st gear has to do with a combination of engine braking and throttle application. Cars with really sensitive throttle pedals or ones with throttle pedal that's like a on/off switch would tend to buck at low speeds. When your car transitions from engine braking to accelerating when you're varying the throttle input is when the bucking happens I think. At least that's my theory.

DBW as always plays a major role in this. Next time, try to be really smooth with throttle application, see if that gets rid of the bucking.

[rml605]

hey havoktsx, you have the 08 which has different upgrades then my 04, but have you notices any "bouncing" of the car and RPMs on shifts 1-3? I don't know if it's jsut a timing issue or what for me, but mine does it. And if im in 2nd, get off throttle, than back on to accelarate, it bounces.

[havoktsx]

hey havoktsx, you have the 08 which has different upgrades then my 04, but have you notices any "bouncing" of the car and RPMs on shifts 1-3? I don't know if it's jsut a timing issue or what for me, but mine does it. And if im in 2nd, get off throttle, than back on to accelarate, it bounces.

i don't think our k24a2 motors are that much different. slightly different exhaust tuning is what gives my car a bit more hp but i think that's about it. you can look up k20a.org for more info on our motors.

per your question: i haven't seen any "bouncing". i'm trying to not look at the tach but go by feel. i do, however, see the tach in my peripheral vision so i do have a good guess of where i am. but i haven't seen any "bouncing". you mean like rev-hang...?

the only "bouncing" i can think of is iirc our ecu's are programmed to burn off excess fuel when throttle is off so you might see a slight increase in rpm but don't quote me on that...

[ClutchFork]

I don't know if it is just the throttle sensitivity. My truck will buck at idle in first gear and I am not even using the throttle.

Also I don't think engine size is it because my old truck had a 4.9L and it would buck at idle on a cold engine.

[havoktsx]

I don't know if it is just the throttle sensitivity. My truck will buck at idle in first gear and I am not even using the throttle.

Also I don't think engine size is it because my old truck had a 4.9L and it would buck at idle on a cold engine.

so for the gurus out there: how in the world do we control/avoid/minimize the bucking?

i've been clutching in every time i feel that first buck and ease out the clutch to "smooth" out the bucking... probably not the best way to save the clutch but this is all within 750 (idle) rpm to about 1200 rpm...

[ClutchDisc]

Not sure, mine doesn't buck unless you let the clutch out too fast when downshifting from second to first.

[rml605]

I don't know if it is just the throttle sensitivity. My truck will buck at idle in first gear and I am not even using the throttle.

Also I don't think engine size is it because my old truck had a 4.9L and it would buck at idle on a cold engine.

so for the gurus out there: how in the world do we control/avoid/minimize the bucking?

i've been clutching in every time i feel that first buck and ease out the clutch to "smooth" out the bucking... probably not the best way to save the clutch but this is all within 750 (idle) rpm to about 1200 rpm...

I can usually control the "hopping" pretty well, let's say if im strolling through a lot by just my foot being constant on the gas. If does start to get crazy i'll just clutch in or go to N and see saw between 1st and N.

Our car is really bad in low speeds, though. I remember when I had my GF awhile back in my car, I was creeping in traffic and the bucking was REALLY bad. She was like.."Is it something wrong with your car? Why the hell is it bouncing up and down?"

[theholycow]

how in the world do we control/avoid/minimize the bucking?

Keep rollin'
Keep clutchin'

Knowin' you can always slip the clutch
for sure
that's what clutch is for

For bucking
And jerking
Clutch will smooth your ride forever more
That's what clutch is for



Seriously, your clutch will be fine, the amount of work you're asking it to do by smoothing out that ride is small compared to a launch or a high-RPM shift. If you can do it by being a smooth operator on the accelerator, even better. You may also help things by smoothly using the brake, it's worth a try though it's more likely to exacerbate the situation.