Trying to narrow down an air/fuel issue... (SOLVED! - TPS Recalibration)

[VirginiaJim]

Do you know how hard it is to get to the plugs and wires?

[tomp]

Do you know how hard it is to get to the plugs and wires?

You have to remove the tupperware to get to the plugs, so I guess, go ahead and paint. 

[B.D.F.]

Yep, I did say that and I even thought of a method to sort of have the throttle end up in the same place. I just have not gotten to it yet- busy as hell with getting ready for winter, family issues (all good, just time consuming) and dealing with a [new to me] vehicle that is throwing problems at me faster than I can throw them back. But as I said, I will try this calibration thing- as my bike runs well now, I really can only look for poorer running but that too would be evidence.

There is another gentleman out there who has O2 sensors on his bike and he (I do not.... yet) and he would the the ideal candidate to test out this idea as he can produce data as a result. If the throttle really does recalibrate, he should note the mixture changes immediately. Further, he should be able to make them both more lean and then more rich at will simply by hedging the throttle position information in the ECU one way and then the other. But I will not call him out on this.... :-)

Brian

Brian said he was going to try it, but I don't remember ever seeing a report.  I tried it and it did drop the idle down a little, but I never had any problems per se, before the recalibration.

[Rembrant]

Then you probably wont notice a difference.  This seems to only help bikes that have a really choppy or hesitant throttle. 

That said, It's mechanical and electronic components working together. In a perfect wprld, these would be completely set from the factory, but there's no exact number.  Some throttles will be at .68V, some may be at .70V at idle. I ASSUME (read; Ass-u-me) that at the factory they program the ECU to read .68V (or whatever the actual number is) as closed/ Idle, and if there's any variance from that, thats where the issues will start. But some bikes naturally are exactly dead on...  I could be COMPLETELY wrong on that tho... and Probably am.

Actually, the TPS numbers are set in the ECU, and the TPS is set mechanically on the side of the throttlebodies. The TPS actually has nothing to do with the idle of the engine. The idle is set by the screw adjuster that sets where the throttle plates stop. The ECU then controls the amount of fuel for the idle speed using the IAP map (Idle Air Pressure). Unlike the TPS fuel maps, the IAP map is controlled by RPM and pressure differential across the throttle plates. So, when you adjust the idle cable/screw, you're adjusting the throttle plates, which changes the air flow across them....thus changing the pressure differential.

This is what is taking place from closed throttle to approximately 10% throttle, so the TPS is not utilized until the throttle is twisted 10% open.

See, the fuel mapping in these ECU's is a little more crude than most people realize. The changes the ECU can make are not infinite. The ECU only adjusts TPS fueling approximately every 7% of throttle rotation. This is why there is an IAP map in the first place to control the idle. If the ECU tried to use the TPS map to control idle, it would be far too crude, and a quarter turn on the adjuster might not do anything....a full turn on the adjuster might not do anything.

So, if that isn't too confusing, it's easy to see why the closed throttle TPS voltage variances are really irrelevant with regards to idle. As I said earlier...several factors are going to effect that voltage...throttle cables, throttle plate linkages/pivots, throttlebody cleanliness, etc. When I checked mine, several times, the closed throttle TPS voltage varied between .66v and .69v, and it made no changes in the idle. As I said above, the ECU doesn't care what that voltage is until the throttle is 10% open or more.

And besides, 0.03v changes in TPS voltages aren't really going to change anything, because the ECU is looking for bigger differences.

Clear as mud?...lol,

Rem

[maxtog]

Well, I guess if everyone is doing it, I might as well too..

LOL!
I have just been watching with interest.  I have no such hesitation or issues on my 2011 C14, so I don't want to press my luck.  But I will be sure to try this voodoo if such issues arise.

[Rembrant]

There is another gentleman out there who has O2 sensors on his bike and he (I do not.... yet) and he would the the ideal candidate to test out this idea as he can produce data as a result. If the throttle really does recalibrate, he should note the mixture changes immediately. Further, he should be able to make them both more lean and then more rich at will simply by hedging the throttle position information in the ECU one way and then the other. But I will not call him out on this.... :-)

Brian

If you hook me up with some clam chowdah, then I'll do some testing for ya...lol.

Another thing to consider that I don't think has been mentioned. If you incorrectly calibrated a TPS....like what was done earlier, so that 25% of throttle was actually set to zero, and 100% was still 100%, you would effectively create a very quick turn throttle...I'm not going to ge my protractor out....lol, but lets say it would go from being a 1/4 turn throttle to being a 1/5 turn throttle, and I didn't see that in the video....

Just something to ponder eh?...

Rem...
Over here thinkin' and stuff

[Son of Pappy]

Serious question, what is the other side saying in regards this new, apparently effective, technique?

[martin_14]

 

[Conrad]

bump.

After analysing the theory behind it, I gave a try to this procedure. Sure enough, I noticed a few things:

- idle went down by about 150 rpm. I like it at 1150 and it went down to 1000. Same temperature, etc. It just went down.

- hesitation is gone. Period. I have been fighting this phenomenon since day 1 and been nothing but frustrated. When I first got the bike I was amazed at how tame it was, but after a while I wanted a 1352 cc engine (which I paid for), not a 600 cc. So flies out, PCV in. Power and torque were restored, specially under 4000 rpm, but the hesitation (coughing) continued. That off-on throttle counter-explosion that bothered me every single time. Next I added a throttle tamer. Better, but absolutely still there. It just got easier to avoid it by being gentle, but I don't like being gentle when I'm chasing (or, more often than not, being chased by) my friends in their bikes. Now it's solved. I just can't get her to do it. It's great.

- I have to sell this bike. I will kill myself. I'm so happy with how the engine responds, specially when I see small gaps in traffic that I usually gave up on because of the stupid hesitation. Now I just take them, because the bikes shoots forward every time I touch the gas. It's exhilarating.

Me happy.

Martin, did you perform the procedure on your bike after it was warmed up or before?

[VirginiaJim]

Serious question, what is the other side saying in regards this new, apparently effective, technique?

Which other side?

[B.D.F.]

Yeah, what Jim said.... who is, or who are the 'other side'? Did we pick teams or something?

I thought it was just people talking about how a mechanism might or might not work on a C-14. ??

Brian

Serious question, what is the other side saying in regards this new, apparently effective, technique?

[B.D.F.]

I know just the place- best chodah in the state. They use cream and butter rather than milk and [I don't even want to think about the butter replacement]. Thick, outstanding clam chowdah. The best clam cakes too- no spitting shell when eating them. So you're on.....

Just a thought but here is what I would LOVE to see: show a short plot of the A/F mixture with your bike running at, say, 2,500 RPM as it does normally. The 'calibrate' the throttle but set it so closed is really 10% open. Then again show the A/F mixture at the same speed and load if possible; it should be very significantly off. It would be even better if you could find out what cells you are using in the ECU for these running parameters but I don't know if that is available or not. But I do believe you can capture throttle position, engine speed, and mixture, right? If so, that alone will show a drastically 'wrong' setting if you can recalibrate the throttle.

Brian

If you hook me up with some clam chowdah, then I'll do some testing for ya...lol.

Another thing to consider that I don't think has been mentioned. If you incorrectly calibrated a TPS....like what was done earlier, so that 25% of throttle was actually set to zero, and 100% was still 100%, you would effectively create a very quick turn throttle...I'm not going to ge my protractor out....lol, but lets say it would go from being a 1/4 turn throttle to being a 1/5 turn throttle, and I didn't see that in the video....

Just something to ponder eh?...

Rem...
Over here thinkin' and stuff

[VirginiaJim]

Yeah, what Jim said.... who is, or who are the 'other side'? Did we pick teams or something?

I thought it was just people talking about how a mechanism might or might not work on a C-14. ??

Brian

Brian is correct..  Our brother site in the UK has picked up on this as well.  Bully for them!  (standard disclaimer:  I'm not advocating this witchcraft in TPS recalibration, however it does appear to be benign and the only possible injury that may occur is a wrist sprain.  Of course I do advocate doing this in the privacy of your garage with no one watching.)

[Stephen.G.Fiddes]

Brian is correct..  Our brother site in the UK has picked up on this as well.  Bully for them!

Probably cause I posted it up on the Face-Space. I know there were a couple UK guys that chimed in on that thread going bonkers cause it worked.

[Stephen.G.Fiddes]

Actually, the TPS numbers are set in the ECU, and the TPS is set mechanically on the side of the throttlebodies. The TPS actually has nothing to do with the idle of the engine. The idle is set by the screw adjuster that sets where the throttle plates stop. The ECU then controls the amount of fuel for the idle speed using the IAP map (Idle Air Pressure). Unlike the TPS fuel maps, the IAP map is controlled by RPM and pressure differential across the throttle plates. So, when you adjust the idle cable/screw, you're adjusting the throttle plates, which changes the air flow across them....thus changing the pressure differential.

This is what is taking place from closed throttle to approximately 10% throttle, so the TPS is not utilized until the throttle is twisted 10% open.

See, the fuel mapping in these ECU's is a little more crude than most people realize. The changes the ECU can make are not infinite. The ECU only adjusts TPS fueling approximately every 7% of throttle rotation. This is why there is an IAP map in the first place to control the idle. If the ECU tried to use the TPS map to control idle, it would be far too crude, and a quarter turn on the adjuster might not do anything....a full turn on the adjuster might not do anything.

So, if that isn't too confusing, it's easy to see why the closed throttle TPS voltage variances are really irrelevant with regards to idle. As I said earlier...several factors are going to effect that voltage...throttle cables, throttle plate linkages/pivots, throttlebody cleanliness, etc. When I checked mine, several times, the closed throttle TPS voltage varied between .66v and .69v, and it made no changes in the idle. As I said above, the ECU doesn't care what that voltage is until the throttle is 10% open or more.

And besides, 0.03v changes in TPS voltages aren't really going to change anything, because the ECU is looking for bigger differences.

Clear as mud?...lol,

Rem

Ok, well now I'm really confused as to why this works... I know your above post has been stated before earlier in this thread, but that one made sense to me. (maybe cause I just had my coffee...)   Looks like I need to update the chart... Again...


Unless... Unless...   Maybe by doing this calibration, the ECU knows better where the throttle is, so it can change maps smoother? 


EDIT:  I love this thread and all the information being tossed around... I'm learning a ton and it's making me really think.

[B.D.F.]

Bingo! That is my interest in its entirety- I want to know what is going on so I understand how it works (the ECU and the possibility of calibration). I do not care about the running characteristics and how they change, at least not  yet, but I have to understand how this calibration function, well, functions. That is why I gave the reasons I did for thinking it does not actually work- not because I really care if it does work or not, and not to argue with anyone but according to my experience (and I have written a lot of commercial machine code and a lot of 'calibration' procedures), common sense and understanding of how things are done according to convention, this would be something between a bad idea and a disaster for any manufacturer to have machinery in the field that owners could make such fundamental adjustments to without sufficient barriers.

And that is why I specifically recommended [the guy I will not mention again] do some specific tests because they will yield data in the form of air / fuel ratios and especially, any changes in them. Things like 'it runs a bit better' are not really what I look for in 'definitive'.

Remember, 'Kill the virgin, grow the corn' worked for millennia because everyone could clearly see that it worked. And over and over again too boot.

Brian

<snip>

EDIT:  I love this thread and all the information being tossed around... I'm learning a ton and it's making me really think.

[Son of Pappy]

Which other side?

I shoulda said "Sides", as in COG or other forums.

[Stephen.G.Fiddes]

I shoulda said "Sides", as in COG or other forums.

I posted it in the other forum, guys have been having good luck with it.  All credit is being given, and it appears that all of the actual research is being done here (which is good cause the notes all flow rather than being split in 2 places).  Once we have a definitive "Why" I will post that in the thread on the COG forum too. (once again, giving credit where credit is due).

[Son of Pappy]

No credit required, I have all I need in knowing what I know.  I got so much help from this forum (old time one, and current) I like knowing I gave something new and unique back and it was just on a hunch.

Like Brian and others, I am curious as to how this isn't part of any manual.  Maybe I should rush out and get a patent?    JK of course.

[B.D.F.]

Not to worry Chet, all the credit for all of.... this..... is yours!     Figure out the secret code to 1) activate power reverse and even better 2) activate the supercharger and you could be the next president of the US of A!  Which no sane person would want to be but that is another matter. 

But I just have that inherent need to know how and why something works, not just that it does. And if this sequence does in fact do anything (and I am not saying it does not, just need to see some data) then I will have to know if this is a built- in feature or some type of flaw in the ECU that just happens to live on in the software. Just as an example, perhaps this is a calibration feature that was supposed to be used by the mfg. and whatever ends the function is either not working or not present.

I think I have a favor or two left with Kawasaki and if this ends up being an open loop, I will try and pursue this one with them. I still cannot imagine for the life of me why they would purposely put in anything like this and not document it as it is absolutely going to cause problems that dealers cannot readily fix due to its being undocumentated.

Brian

No credit required, I have all I need in knowing what I know.  I got so much help from this forum (old time one, and current) I like knowing I gave something new and unique back and it was just on a hunch.

Like Brian and others, I am curious as to how this isn't part of any manual.  Maybe I should rush out and get a patent?    JK of course.