does anybody have the same issue as me......does anybody notice when u let go of the gas and then press on the gas again the car kinda "laggs" a bit?? i dont kno how else to describe it. does anybody else have that issue???

 

I know what you are talking about.... as I observed the same lagg as well. I dunno... is sounds stupid but I guess it may have to do w. the engine setting... whoever has machanical background may anser this questions.

 

3 words: drive-by-wire

 

It's the electronic throttle. Somehow Acura couldn't get the same level of smoothness that BMW did with electronic throttle.... The TSX has a more defined on-off point, so it jumps in throttle as soon as you pass that point.

 

Yes, I have it also.....its normal.

 

I have experience this several times. Might it have to do with the Drive By Wire that we have on our TSXs?

[EDIT] Took too long to login to reply. But I guess it is the Drive By Wire.

 

This make more sense to me.... I had a 02 Civic and I believed it is drive-by-wire as well but I didn't feel such lagg.

 

IIRC, only the 2006 Civics have DBW.

 

I see.... thx!

 

Common. It has to do with the fuel injectors. When you take your foot off the gas, the FI's shut off. That surge is from the FI's kicking back in. I took mine in a long time ago and this is what an Acura tech told me...

 

it cant b fuel injectors. If the injectors shut off that means there wouldnt b any fuel goin into the combustion chamber if u stop at a red light or anytime ur foot is off the accelerator. that would just cause ur motor to cut off at every red light u go to. the guy who told u that is full of crap. he should not b workin there

 

It has nothing to do with idling at a stop. Under closed throttle engine braking(the crankshaft is connected and rotating through the driveline) and under certain parameters (temp etc), the fuel delivery is cut off as a polution control and fuel economy measure. Good thing you're not working there.

 

thanks for everybody replying back. i guess i'm not the only person experencing it. BTW i have a 6MT. i was hoping there is a solution to this but guess not. oh wells

 

The solution is to stay at full throttle as much as you can

 

true true!!! lol

 

Most Fuel Injected cars from the late 70s shut off the injectors when decelerating--if engine speed rises above, say, 1500 RPM (for example), and the throttle is shut (as indicated by a throttle switch), the injectors are not triggered. Then, as the engine speed falls below 1200 RPM (for example), the injectors will turn back on. This is an emissions/economy measure, and it eliminates popping in the exhaust as you decelerate.

Anyway... the turn-on and turn-off of this mode is far from graceful in the TSX. This is probably due in part to the lag inherent in the drive-by-wire throttle, as well as the actual throttle position required (accelerator has to be depressed more than in most cars).

Call me spoiled by other cars, but this behavior sort of takes away from what is otherwise an extremely enjoyable car to drive. I hope that a modification is available soon to address this issue. I also wish Honda had some kind of feedback forum that actually made a difference.

 

its nice to see other people who thought the same thing. The worst is at low speeds like parking lot speeds 5-15 mph. Such a jerky car when your at slow speed on and off the gas.

 

especially in parking lots!! it really annoys the crap out of me!! like what junktionfet said hope theere is a modification available soon to address this issue. kinda sucks when u have other passengers int he car, seeing there head rocking back and forth. kinda funny too sumtimes.lol

 

I know..... I felt exactly the way you feel... jus take it easy on the gas peddle.... do not slam on it too hard!!

 

Alabama...huh...

 

When I add gas, I get the nasty jerk as well as my tach jumping ~100 rpm and then falling back before the car resumes normal acceleration. Is this normal? It seems to be much more worse at the lower gears.

 

its just noticable in city traffic/parking/slow speed. I have no complaints at highway speed. but yea at 10mph letting off the gas and then pressing it slightly was almost bad enough to make me think my car had something wrong with it.

 

Interesting. Mine happens even in 3rd, 4th gear. I left off the gas for a few seconds, then softly apply gas and the car noticably jumps at initial accelleration. I don't recall the car doing this when it was new.

 

I found a previous thread that answers my question and others in this thread:

https://acurazine.com/forums/showthread.php?t=25859

But my main concern are my rpms jumping a bit...I'm curious if this is normal as well since it hasn't been noted by anyone else.

 

Throttle back and the i-vtec against seraches for the best torque peak so you get this lagggg..... Normal.. This is what we call slight hesistation as the VTC gets to work... if you change your air intake to open pod, you will notice the difference less gradual as more air flow intake...

 

At low RPM and light/part load, I would've assumed that the VTC mechanism is used to help mix exhaust gas with the intake charge, since the TSX doesn't literally have an EGR valve... and it most certainly needs one to accompany that ridiculous compression ratio. Then at full load, I would expect it to sweep in proportion to engine speed--continuously varying the overlap.

I can't imagine it tries to vary torque output of the engine based on throttle position--that's essentially fighting the throttle, which seems pretty silly to me. And what would be the point at light load anyway?

I believe the lag that most people describe is due to the throttle. With a resonator-less intake, you can hear it. The sound increases in proportion with throttle angle, and your foot moves in advance of this sound.

 

The VTC has a slight hesitation and if you read the orginal thread, the accelerator was depressed and then pressed. This increase puts the VTC to max work and thus this hesitation.......

 

I did read the original thread. The author said that when he releases the throttle then depresses it again, he feels a lag in response. I am assuming that this person is driving normally and taking the engine from part-load, to no-load, and back to part-load. So again, I'm curious why VTC would be doing anything to enhance torque dynamically at part load. Seems like it would only add insult to injury.

 

The VTC will "optimise" the torque as at lower end speed, the car needs more torque than horses. This was the basic fundmental flaw of traditional Honda VTEC engines like teh B series. The I-vtec was introduced to counter the low end torque, however, it is like an auto gear, has a slight hesistation due to mechanical means integrating the response..

 

just came to my thought......for those who has their ECU reflash and or with a SC, dou peeps still feel the jumpyness??

 

Adjusting intake and exhaust cam overlap (via intake cam VTC) will make an insignificant change in torque when the pumping losses from a partially open throttle are taken into account. The only possible value VTC has at part throttle is the emulation of an EGR valve--which is actually sort of ingenious in itself.

If VTC was used exclusively for enhancing torque from the engine, it stands to reason that its operation would be directed by engine speed. Engine speed doesn't change much when going on-off throttle... unless of course you have an Automatic and you've caused it to kickdown. However even that wouldn't be the case because Honda automatics are notoriously slow to respond to pedal input.

Without a doubt, the lag is induced by the drive-by-wire throttle. I suspect that it is just a simple engineering blackhole--like a filter cap that is too large on the output of the pedal unit. It behaves as if this is the case--quick response when the pedal is modulated slightly at the very bottom and very top of the pedal travel, with the slowest response in the middle of the pedal travel or when the pedal is taken from zero to full. Test it for yourself and you'll see.

 

OK, will try out my manual . My hesitation is when I step on the gas pedal at each switch of gear while acclerating. We have even found that we could wheel spin at 2nd gear....like if though the damn VTC kicked in....

 

I went to the dealer (Acura Optima in Quebec city) last week to test drive a 06, and the difference is quite noticable. I would say that the problem is fixed indeed. Good. So someone somewhere at Honda has the solution. So I went to talk with the service supervisor...

He said that the "jumpyness" is a normal characteristic of the 04 wich is not adressed by any TSB and that Acura will not issue any instruction as how to make the 04 behave like an 06 and that if I don't like that behaviour of the car, I just have to buy an 06... simple!!! Now I'm happy. The second solution that he proposed was to change parts at random until we find wich one cures it without knowing if it any part make a difference since it can also be a software feature that won't be compatible with the 04 ECU.

I really don't mind paying for parts or a brand new ECU or reflash but I want to be sure that it will make a difference. I'll try to get a better answer from Acura Canada but I doubt it... they don't seem to care about past issues and only focus on the future. Maybe if we join forces we can make them move?

 

Um... unless it was addressed in the later '06s, i've got one of the earlier '06s and this jumpy behaviour/lag when switching from 1st to 2nd is definitely there and is annoying. The options I have is either to rev the shit out of it or ride the clutch.

Winter's coming around and I can't be reving it like that and as for riding the clutch... not an option.

 

The "problem" here is not when shifting. It's about the fact that you can't get back smoothly on the throttle when you let it go completely since the DBW system is in fact driving the throttle body and injection in a way that make you look like you don't know how to drive.

The best way to experience it is to drive at a constant speed between 40 and 50 MPH in 3rd or 4th gear, let go the throttle (like you do when getting in a curve or trying to follow the traffic in front of you) then apply some throttle smoothly. The throttle doesn't seem to respond right away and then "Bahm"... This "characteristic" of the 04-05 cars will surely induce some understeer when coming out of a curve on a slipery winter road surface... That's why I'd like to cure it by learning what was changed on the 06.