allmotor_2000

Guys... little 'feature' I found out today on the 6spd.

Try this first:

Warm up the car... then cruise around at around 2500 rpm in 1st gear. Floor the throttle very quickly and tell me if you feel a little 'lag' just before the rpms start climbing.

Now... disconnect the speed-sensor and try it again. The response is immediate and the tires just spin until the limiter kicks in at 5.5K (because the speed-sensor is disconnected, VTEC does not activate, NAV doesn't work, DTC codes, blah, blah).

I am trying to figure out if this has to do with the TPS (Throttle Position Sensor - something is de-activated when the ECU doesn't get a speed signal), or something electronic with the tranny (this might be far-fetched...)

This might be something common to all 6spds, or just my car because I was screwing around with the Throttle Body, TPS and MAP sensors recently.

Now, if this is a common feature, then what remedies are there. You can't drive around without the speed-sensor obviously, but there might be another way??

allmotor_2000

No one tried this yet?? C'mon guys this might affect all 6spd owners!

Nashua_Night_Hawk

ECU needs sometime to compute... you disconnect the speed sensor and you screwed the ECU.... leave it alone...

allmotor_2000

The ECU does not 'need time to compute'! This is not Microsoft Windows here...

If there is another sensor to bypass this 'lag' in throttle response then all the better. Obviously the car isn't quite drivable without the speed-sensor.

If you had a 6spd, you'd know what I mean here.

My concern here is that there might be other 'limitations' imposed by the ECU on this car... sort of to tame the sucker, if you know what I mean.

scalbert

I just got around to reading the forum today and we drove my wife's car today.

Are you refering to the VSS on the output of the transmission?? You would be surprised hom much the vehicle relys on the VSS to operate. In the automatics the shifts are based on speed and not RPM which seems reversed to me. I would assume that there are various aspects which the ECU uses the VSS signal for even in the manuals.

About the original topic, I'll try and check this tonight if it is not raining otherwise it will be tomorrow. But I don't recall this ever happening though.

NOLACLS

I have felt the same thing to but I thought it was the dip in the power band that I have seen on other dynos on here. Like when I go out of a parking lot slow in first then I floor it once im in the street it like lags (low on the power) but then it goes....is this what your talking about???

allmotor_2000

Yes... just cruise slowly at around 2.5K in 1st gear. Make sure the
engine is warm etc. (to eliminate other variables). Now punch it and you will notice a momentary 'lag' before the rpms begin to pick up.

Now, disconnect the VSS and try it again. Throttle response is immediate. Do keep in mind that VTEC does not activate if VSS is disconnected. If the check engine light comes on, the rev-limit is also lowered to around 5.5K, so don't push it past that. But throttle response is MUCH better.

You can try this at 3K, 3.5K or even 4K rpms and the effect is the same - meaning, its not a dip in the power-band.

You might not notice this 'lag' unless you have tried it with the VSS disconnected (the VSS is located just to the right of the starter... black connector on the right-side-front of the tranny.

typeR

it sounds like maybe youre preventing the actuator from opening and if you look at the dyno ther is a dip when that occurs right at 3800

allmotor_2000

I verified the actuator... it works fine. Also that doesn't open until much higher in the rpm band.

acur8ly

iTrader: (1)

I dont have a 6 speed but I know about the lag that u are talking about. I wish I knew how to get rid of it. You have to admit that when the power actually kicks in the car pulls hard as shi*

EricL

A wild guess...

It could actually be emissions related or related to prevent" people from "bucking" the car (torque limiting)...


In the autos, the ignition is retarded on shifts, and older emission vehicles that I got my hands into had mods that allowed for a pretty soft throttle transition until a few changes were performed...

allmotor_2000

It does feel like timing is retarded a good 10-15 degrees for that second or part of a second and probably must be more to prevent damage to the drivetrain (??) rather than emissions. Usually for the emissions test they maintain RPMS at 1500 and/or 3500 for a half-minute or so on the rollers while exhaust emissions are measured... they don't throttle the car from what I know. It might be the case when a certain model is being introduced, more exhaustive emissions testing might be the protocol.

It's fully understandable for auto's, but on manual-tranny cars... its pretty lame. This does happen in all gears... its only in 1st that is very noticeable. I am sure if this 'feature' is disabled you gain a tenth or more down the 1/4. Remember there are 3 gear-changes and one launch.

BMW's like the M5 gloat their 'instant throttle response' with the electronic butterfly throttles... Acura seems to be doing the opposite here!

EricL

RE: Emissions -- the roller test is a CA test for getting an idea of amount of filth per unit volume and the test you mentioned is used for “re-testing” (tell me if I am way out of date).. It doesn't have a clue about the "total" emissions that a given car produces. So, as to the "exact" cycle being used, it depends. The computer is going to have a "finite" amount of time to adjust to a change in current operation, so, its possible that their are "transient" emissions that would show up on during "new car" testing that is measured as "total exhaust" during a pre-programmed cycle. I have no idea how fast the "ramp" time is, so this may be a non-issue.

AND

After the current round of automatic failures, I'm pretty sure that Acura is a bit shy of pressing the power on some of their components (who can know for sure). Have you ever seen someone with a "fast responding throttle" "buck a car"? If the TP is fast enough, you can snap the half-shafts off by getting the car into an oscillation by “pumping” the throttle in low gear. (I'm not saying that was priority #1, but not everyone is going to be "nice" to their cars...)

AND

You there is always that "build for lowest common user" thread going on sometimes... At a minimum, a brutal stab of power (in the wet) + torque steer could cause some grief...


(I personally hate any kind of lag like that... but have seen some real idiots do some horrible things to a car and need to be protected from themselves and the car from them. Perhaps a "qualified"/"unqualified" switch can be added to some of the cars -- similar to "Sports"/"Auto"/"Lame-o" settings... )

allmotor_2000

I just want to find out a more diligent way of getting rid of it... the disconnecting the VSS is not the way to go about it!

PlayaZ

keep workin, your onto something, just dont break ur ride and come back sayin acura f'd you

EricL

Pioneer it...

Well...

1. I keep hearing people "claim" that Jet can get into the ECU (top speed limiter removed, better butt dynos).

2. Then I hear that the current boxes use a custom IC foundry to make their chip and it has a custom instruction set with no ability to flash it...

IF you could verify #1 (that Jet isn't full of it -- and I have doubts), perhaps they can "patch" the piece of code that is bugging you...

An "analog"/"add-on" solution is possible, but messy...


What about the upcoming AEM EMS for the 2001-200x CLS????

GreenMonster

I guess I'll have to break down and buy the Helms manuals so that I'll know WTF you guys are talking about If I'm good maybe Santa will bring me Helms manuals for Xmas.

I'll have to pay attention while revving it out in first gear tomorrow.

scalbert

I never got to try it last night and we again drove my wife's car into the office. But I will soon try it.

But for reasons why they do this and seems to be related to speed, it would probably be for the jarring affect. They may have turned this off to onn throttle response to reduce potential issues with drivers who may not be as experienced.

But this does not seem to be an issue with part to full throttle response.

I'm bringing my laptop home Thursday night and will try this out. I'll capture some logs on ignition advance and throttle input so we can compare.

allmotor_2000

Sounds good... it will be interesting data.

scalbert

I didn't bring home my laptop tonight but I did go out for a quick drive. But unfortunately (or maybe fortunately) I did not have the same symptoms. When I floored it in 1st at about 2500 revs from a completely off throttle stomp, I spun hard. This happened every time I tried it and the spinning was not short, it went to at least 4500 revs before I let off (I was near my neighborhood).

Which sensor did you unhooked?? After looking at the manual we have two possible speed sensors, a NC (Counter Shaft Speed Sensor) and a NM (Main Shaft Speed Sensor). Which is the actual input that determine the VSS I haven't found, but both are on the transmission and potentials. So by determining which you unhooked might help...

Wires

Hmmm.... I get the same problem as Allmotor_2000 does. Bastard! I never noticed it until he said something! It feels like a slight lag when you punch the throttle, and then the car perks up and goes.

hughesne

I tried this last night, and i had the same response as Scalbert. I just spun hard till redline, no lag, and then shifted to 3rd to shut the thing up.

NOLACLS

I think you can only feel it in first not 2nd.....unless you just skipped 2nd and from 1st to 3rd...ignore me if thats the case

I have the same result as allmotor...little lag and then go but I thought that was just where the dip in the power band is...but now that I think about it I think its higher...more like 3500?!?!

hughesne

Yeah, i went from 1st to 3rd because i knew that shifting to 2nd would continue to wake my neighbors.

GreenMonster

I agree with both camps

My 6spd did seem to lag a bit in 1st when floored, but I think it's due to the fact that the torque curve doesn't flatten out/fatten up till about 3000 rpm. The engine revs slowly from 2500-3000 rpms, but it tachs nicely from there up to 6000 (only 800 miles on my CLS, so I haven't taken it to redline yet )

One thing is for sure, you better have the front wheels pointed in the right direction before you floor it

NOLACLS

juuuust checking.


You are right Green...LSD owns

allmotor_2000

Now... this is the result I was not hoping for. I figured everybody was experiencing this.

Here is a link to the sensor I disconnected:

http://photos.yahoo.com/bc/gunjan_ra...s+Toys&.view=t

Look for the VSS Sensor Picture (last one).

This is something I wish to correct... so any help would be appreciated.

scalbert

That looks like it is the Main Shaft Speed Sensor but I will verify it tonight.

allmotor_2000

I was pretty bummed after reading all this in the morning, so I tried all sorts of things on my way to work today. I floored the car immediateley after starting it (I shouldn't do this... but one-time won't hurt). Anyways... the problem wasn't there... it just spun (although VTEC doesn't work when the engine is cold). After the motor warms up... it happens again.

Few things with the VSS. Once disconnected, it also disengages the shift 'protection' feature which prevents you from going into reverse while moving forward (obviously to do with VSS).

allmotor_2000

This is so damn annoying... never had a car that does this. Don't get me wrong... it pulls like crazy after this little 'lag'... so much so that I usually spin a little from 6K to 7K in 1st gear. I'd just rather spin from 3K to 7K

Wires

I tried it again tonight. I pulled the plug on the sensor, and the lag was gone. I put it back on, lag came back. It didn't feel any stronger though. Pulled the same through the entire power band for me (just was a slight delay before it pulls with the sensor on).



Ok... that adds 2 things to my 6 speed list. The lag, and that stupid stumble the engine has going from open loop to closed loop mode on cold starts.

:o

NOLACLS

Can you explain that a little more?


I have not pulled any plugs but I DO have the lag when I stomp it I dont know if it has always been there but I noticed it a few weeks ago...could have been there from day one for all I know....now someone anyone find a fix for it

scalbert

That turns out to be the Countershaft Speed Sensor now that I have checked against the manual.

Now why would there be a delay for you without the sensor hooked up?? Obviously this is ECU related as that is the only point where the subject signal is used. So how can it be corrected; through ECU re-programming which is not currently available. But it still doesn't answer the question about why it occurs.

What would cause a momentary lull in power would be thing like ignition differences or altered fuel supply. But in this case I can not see why fueling would change. So potentially without a speed signal there is a loop in the ECU that doesn't get altered accordingly. Other loops (or threads to you programmers) are running with their inputs but without the vehicle speed the timing gets set with a serious advance inadvertently.

This is most likely this issue and is not easily overcome. We will probably have to wait for the reprogrammed ECU to come out (which it will eventually). With direct ignition it is hard to alter the timing outside of the ECU.

Wires

I had athread a while back, and it seems like it's related to both the 6 speed and auto versions in '03. When you start the car with the engine cold (i.e. morning, or afterwork), the car runs fine for about 5 minutes, and then (when driving with constant throttle -- you won't feel it when stopped at a light), the car feels like the engine dies, and then picks up again. Somedays (I suppose it depends on the amount of throttle, gear, temp, etc) it's pretty nasty!

Best way to simulate it is put it in a higher gear (say 4th), with the engine revving at say 2000RPM. Keep constant speed, and then take your foot off the gas quickly, and then hit the gas quickly. That same lurge is what I get.

oghondaman

So many variables to consider but, I agree with scalbert,must be going into a richened ecu limp mode with sensor dissconected

Wires

Ok, I tried it again this morning, but I think it's not as simples as just the unplugging the connector.

Here's my deal. It's 29F out this morning, pavement is dry. I tried it last night, and found that hitting the rev limiter makes the MIL come on. Oh well, That's what I bought the OBDII tool for.

Ok, so this morning the MIL is still on, and the connector is hooked up.

I'm driving in 3rd, and I downshift on the turn into 1st, rev's jump up, and I let them hit at 2500RPM for a second, crack the throttle, the tires chirp and way it goes.

I'm thinking... Hmmm... that's not right, so I brake for another corner in the lot, let it rise to 2500 RPM, and do it again. This time there is a lag.

It seems to make a difference on how you get to 2500 RPM. A downshift is ok, but from a start it isn't.

NOLACLS

AHHHHHHHHHHHHHH thank you so much! I feel the same thing...every morning in the same spot on the way to work....it like almost dies. damn ok well I am glad that it is "supposed" to happen because I was about to go to Acura and see if they can fix it. That would mean I would have to give them my car over night and wait and then they would probably tell me they cat feel it or they dont know what it is. Thank you so much for the info

Sooo it is something that is in need of fixing or is it just like that....cuz I can handel it once in the morning but not if its going to get worse.

allmotor_2000

Wires: It's not 'downshifting' or anything followed by a stomp to make the tires chirp. When the motor is relatively cold... it doesn't 'lag'!! Once it heats up.. no matter how you get to 2500rpm in1st gear... it will start lagging. I notice EXACTLY what you do!!

Wires

I realize that the colder weather is giving me more HP, but I didn't have the lag and got the chirp when I downshifted from 3rd to 1st going into my lot, and then floored it from 2500 RPM. I then braked for a corner, and slowly brought the revs back to 2500 RPM, help it for a sec, and floored it, and no chirp and the lag.

I dunno... I'm just saying I'm having spuratic results.

Wires

Just a FYI:

It's not SUPPOSED to happen, it just seems like the '03 models have this trait (some engineer at Acura probably was tweaking the tables for better emissions when cold, and kind of screwed up.)

I've taken mine in, but they could reproduce the problem. They then gave me some BS about it's the parts are tight, and that's the problem. Ok, whatever. (That was a couple of months ago).

I'd take it in and see (bitch too!) Tell them Mr. Internet says both '03 autos and manuals have this problem. Hopefully it'll become a TSB, and get fixed. It'll be just a computer code upgrade to fix it. I just don't know if it's gotten back to the Acura engineering that there is an issue.