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

[B.D.F.]

No, nothing mechanical can be changed in any way by altering any readings or electronic sensor reports. The throttle position sensor merely reports the radial position of the throttle rod to the ECU, which then uses that data to pick a cell from a look- up table and inject (Easy Boys!) the correct amount of fuel and perhaps set the timing. Changing the calibration of that sensor would result in electronic changes only, nothing mechanical.

The way the throttle position sensor is calibrated at the factory is to set the idle, read the resistance of the TPS sensor and physically rotate it until it reports the correct reading. The service manual will report that the TPS cannot be calibrated but that is not true; it is just not supposed to be calibrated by US in the field. In fact, there are elliptical slots where the screws anchor it for exactly that adjustment.... and they are 'paint locked' at the factory, exactly like the fast idle cam that "cannot" be adjusted either.

Brian

<snip>

Are there stepper motors or secondary sensors at work here that are actually being aletered and/or restored through the open close throttle movements? 

I DON'T KNOW, just wondering, that's all... tomp

[B.D.F.]

The ECU's are different between the bikes sold in the US and Canada, and the rest of the world, and as you mention, the O2 sensor is the major difference. Our bikes do not have them so the ECU would generate a fault if it tried to gather data from them. Besides that, our ECU's and the [non US / Canada] bikes have different part numbers for the ECUs.

But I do not think that makes any different at all to what this thread is about.

Brian

<snip>

Leaves me wondering even deeper, seeing as how the Euro bikes have the narrow band O2 sensor, how does the Euro ECU differ from the rest?  Is it the same? 

<snip>

[just gone]

It SEEMS, that the 0 and 100% voltages would remain the same as Rem showed, but the movement in between was somehow  altered, causing the choppy acceleration when out of calibration.  The recalibration smoothed everything out again. 

Are there stepper motors or secondary sensors at work here that are actually being altered and/or restored through the open close throttle movements? 

I DON'T KNOW, just wondering, that's all... tomp

Not trying to stir anything up either, maybe the placebo effect, maybe not...but I'm not sure what the test voltages Remb' put up prove or disprove, as it's what the ECU does with that information that counts right? I mean the "calibrate TPS procedure ", if it indeed does anything, isn't going to change the output of a sensor but it may change what is done with that information in the ECU. Right?

No, nothing mechanical can be changed in any way by altering any readings or electronic sensor reports. The throttle position sensor merely reports the radial position of the throttle rod to the ECU, which then uses that data to pick a cell from a look- up table and inject (Easy Boys!) the correct amount of fuel and perhaps set the timing. Changing the calibration of that sensor would result in electronic changes only, nothing mechanical.

On a bike with the flies still in (even if reflashed) couldn't a "Calibrate TPS procedure" (again if it really does anything) change how the secondaries open? (stepper motors right?)

[just gone]

I should also mention that my C14 is/was working perfectly fine...no complaints. It does display some throttle snatch, but I think this is pretty common with these FI set-ups. I think it has something to do with the transition from the IAP map to the TPS map, but that's just a guess based on where it happens on my particular bike.

By the way what's an IAP map? I assume it's something to do with idle?

[tomp]

By the way what's an IAP map? I assume it's something to do with idle?

Intake Air Pressure...   More than you ever want to know about Motorcycle FI systems.  The whole book is there, but it links to p58 where the IAP is discussed.  tp

http://books.google.com/books?id=wC2dThrY2BMC&pg=PA58&lpg=PA58&dq=motorcycle+IAP+map&source=bl&ots=jglWURwYdg&sig=TJPc44CtwW1FtvteVYb9akjv-GQ&hl=en&sa=X&ei=eW0XVIvzPKri8gGTgoGwBQ&ved=0CCUQ6AEwAQ#v=onepage&q=motorcycle%20IAP%20map&f=false

[Rembrant]

Not trying to stir anything up either, maybe the placebo effect, maybe not...but I'm not sure what the test voltages Remb' put up prove or disprove, as it's what the ECU does with that information that counts right? I mean the "calibrate TPS procedure ", if it indeed does anything, isn't going to change the output of a sensor but it may change what is done with that information in the ECU. Right?

Well, in order for the ECU to make it's calculations based on where the throttle position is at any given time, it needs to know what voltage is zero (closed throttle), and what voltage is 100% (WOT). The sweep of the TPS...between 0-100% is what the FI ECU is reading. In order to change that 'sweep' data, you would have to change the voltage outputs at 0% and 100% for the ECU to see any change. Does that make any sense? So, all things being relative...if the closed throttle voltage and the wide open throttle voltage don't change, then nothing within the sweep between the two would change either.

By the way what's an IAP map? I assume it's something to do with idle?

Idle Air Pressure. The C14 (and other FI Kawasaki models) actually run on two fuel maps. The engine runs on the IAP map from 0% throttle position to approximately 10% throttle position at which time the ECU switches over to the TPS map. There is a MAP sensor attached to the throttle bodies that is reading the pressure below the throttle plates. This data is compared with the outside air pressure (sensor under the seat).

[B.D.F.]

Yes, you are correct. In processing the analog signal (the voltage sent by the sensor) into digital data that the ECU would actually use, there could be a coefficient in there or possibly even an algorithm to 'map' (and skew) the entire plot of the analog input to the digital map.

But that would defeat the purpose of displaying the information from the KDS because you would be looking at unmodified data that was modified by the ECU without being able to see the actual ECU used data. Put another way, if there was an electronic calibration algorithm, and the diagnostic software did not show it, what would be the point of looking at the raw data feed? That would be like watching the pressure inside the tire with a diagnostic tool only to have the actual TPS sensor alter that reading by compensating with temperature, which is does, and then feed it to the KiPass ECU: you could test the system but would have no idea what data should be showing on the LCD because it was altered after your test point.

Brian

Not trying to stir anything up either, maybe the placebo effect, maybe not...but I'm not sure what the test voltages Remb' put up prove or disprove, as it's what the ECU does with that information that counts right? I mean the "calibrate TPS procedure ", if it indeed does anything, isn't going to change the output of a sensor but it may change what is done with that information in the ECU. Right?

<snip>

[VirginiaJim]

So what happens when the battery is disconnected and then connected?  I'm going to bring my old past Prius into the mix...  I replaced the throttle body assembly cause it was going whacko with the idle and it was setting codes that indicated the TB assembly was the culprit.  I replaced it with a used TB and it ran like  so I figured the car needed to be rebooted and disconnected the battery and connected it back.  It then ran fine.   Seems that the TB recalibrated itself to the ECU or vice versa and it worked fine until I traded it in a 100k miles later.

[B.D.F.]

Unless it had nothing to do with the throttle position sensor at all. I had a Ford Expedition that would 'seek' the lowest possible idle after the ECU was disconnected.... and it would run slower and slower until it got a shot of throttle and ran too fast. It would repeat this cycle over and over again in smaller and smaller increments until viola! a steady idle. All it was was the ECU probing (Easy Boys!) for the low idle threshold of the engine. A typical digital 'learning' tool but usually we (the end user) cannot see them actually work. Then again, Ford has always been rather..... plain in their execution.

And go easy on the technical jargon, would ya'? (I had to look up 'whacko'). 

Brian

So what happens when the battery is disconnected and then connected?  I'm going to bring my old past Prius into the mix...  I replaced the throttle body assembly cause it was going whacko with the idle and it was setting codes that indicated the TB assembly was the culprit.  I replaced it with a used TB and it ran like  so I figured the car needed to be rebooted and disconnected the battery and connected it back.  It then ran fine.   Seems that the TB recalibrated itself to the ECU or vice versa and it worked fine until I traded it in a 100k miles later.

[tomp]

I want my Mikuni carbs and Holley 875's back.  I understand all of the wonderful things FI does for mileage, warm up, altitude changes, and EPA compliance; but it is now virtually impossibe to understand, much less work on the systems, without computers and an engineering degree.   OK, rant over.  I do like that I can get in my car or on my bike and just crank and go, though...

Someone please explain what is happening with the definite  changes in throttle response in the posted video.  That is what this thread is really all about, but we still don't have an answer/understanding of the outcome from actions taken there.  Thanks, tom 

[Rembrant]

I do like that I can get in my car or on my bike and just crank and go, though...

Well that's just it isn't it?...lol. I remember turning my high beam headlights on with my left foot too...good grief...how archaic...lol.

Seriously though, the 'new' EFI equipment...ECU and throttle position sensors, injectors, MAP sensors, etc on all these motorcycles in the past decade or so has made them super reliable. Yes you need special tools to work on them...but that's also because they so rarely ever need work in the first place....and why there are discussions about how incompetent dealerships are...lol.

Rem

[tomp]

Well that's just it isn't it?...lol. I remember turning my high beam headlights on with my left foot too...good grief...how archaic...lol.

Like new cars with the new fangled push button starters.  My dad's 52 Chevy had a little black on button the dash to start the engine.  I believe my 55 Plymouth Belvedere was the same.  Just a key and no FOB.....

[just gone]

Idle Air Pressure. The C14 (and other FI Kawasaki models) actually run on two fuel maps. The engine runs on the IAP map from 0% throttle position to approximately 10% throttle position at which time the ECU switches over to the TPS map. There is a MAP sensor attached to the throttle bodies that is reading the pressure below the throttle plates. This data is compared with the outside air pressure (sensor under the seat).

This makes sense, thanks Remb'.

Well, in order for the ECU to make it's calculations based on where the throttle position is at any given time, it needs to know what voltage is zero (closed throttle), and what voltage is 100% (WOT). The sweep of the TPS...between 0-100% is what the FI ECU is reading. In order to change that 'sweep' data, you would have to change the voltage outputs at 0% and 100% for the ECU to see any change. Does that make any sense? So, all things being relative...if the closed throttle voltage and the wide open throttle voltage don't change, then nothing within the sweep between the two would change either.

Yes, you are correct. In processing the analog signal (the voltage sent by the sensor) into digital data that the ECU would actually use, there could be a coefficient in there or possibly even an algorithm to 'map' (and skew) the entire plot of the analog input to the digital map.

But that would defeat the purpose of displaying the information from the KDS because you would be looking at unmodified data that was modified by the ECU without being able to see the actual ECU used data. Put another way, if there was an electronic calibration algorithm, and the diagnostic software did not show it, what would be the point of looking at the raw data feed? That would be like watching the pressure inside the tire with a diagnostic tool only to have the actual TPS sensor alter that reading by compensating with temperature, which is does, and then feed it to the KiPass ECU: you could test the system but would have no idea what data should be showing on the LCD because it was altered after your test point.

This part not so much. The sensor is going to show the same voltage (within certain tolerances for temp and battery condition etc) but if there really is a "TPS procedure effect" then somewhere is a modified table that says what voltage is a closed throttle and what voltage is an open throttle. In the video he purposely used a throttle lock to set an artificially high closed throttle setting (let's pick a voltage say 1.4 volts or whatever, but more than .68 V ) and then use the real WOT (let's say 3.78 V) and it ran...jumpy... I guess what I'm saying is looking at the voltages from the sensor before and after a "TPS Calibration procedure" doesn't really show anything useful using a KDS or a voltmeter. Obviously a simple On/off ignition with a couple of full throttle pulls in between isn't going to change the sensors function. Am I making sense? It seems that what we want to find with the KDS is a map or table that is significantly changed before and after the procedure is performed. Maybe it jumps from the IAP map to a TPS map at a different point based on what it thinks is a 10% throttle opening is based on a higher voltage because of the bad calibration? I just don't see where the raw data from the sensor could show anything useful (in this instance on this subject {the existance or non existance of a TPS calibration effect}), and I wish I was smart enough to figure out why both of you (who are both smarter than I am ) do?  To my limited thinking ability    this is like testing the input voltage to an old time tube radio (since we seem to be suddenly talking about old stuff as well  )with a tube removed and then replacing the tube and checking the input voltage again and saying the tube isn't needed because the input voltage didn't change, still 115 VAC.

[VirginiaJim]

Well that's just it isn't it?...lol. I remember turning my high beam headlights on with my left foot too...good grief...how archaic...lol.

Rem

Ah sweet memories.  I can still hear the click click of turning the high beams on..also remember using the choke..

[tomp]

Ah sweet memories.  I can still hear the click click of turning the high beams on..also remember using the choke..

Depending on the outside temp, pull the choke lever half or all the way out, and slowly press the lever back in, as the engine warmed.  Also Pouring hot water on the engine and radiator, before we had antifreeze.  Can't remember if the engine ever froze up, but probably did occasionally...

[tweeter55]

Ah sweet memories.  I can still hear the click click of turning the high beams on..also remember using the choke..

Three on the tree...

[tomp]

Three on the tree...

My dad always shifted from 1st to 3rd, thinking he was saving gas and the engine by avoiding 2nd.  Learned it from his dad. 
Dad is 98  now, and hasn't driven in five years.  Gave his last car to me, I gave  it to my son.  Yep, great memories. 

[Son of Pappy]

I just wish Brian would go old school and give it a try.  The old "Trial and error" methodology.  Nothing fancy smancy about it, unless of course he has some kinda Mary Jane Tinklepants kinda burl wood under his side stand

[B.D.F.]

Well, I am kinda' delicate. And it IS cold outside (down in 50's F !). But on top of everything else, I think Cory did the better try 'cause he has data feedback that I do not have.

But besides all that, I think we are in a good place here- we have discussed it pretty thoroughly, various people have tested it and gotten various results. Others will chime in and after a while, the majority will speak so we will have a good result. Hey, it works for elections, right? 

Brian

I just wish Brian would go old school and give it a try.  The old "Trial and error" methodology.  Nothing fancy smancy about it, unless of course he has some kinda Mary Jane Tinklepants kinda burl wood under his side stand

[Stephen.G.Fiddes]

Ok, so my lovely wife took over the BBQ so I could execute this important test...lol. She's so awesome...lol.

Ok, I did four checks with the KDS:

1. Checked my TPS readings when initially turning the bike on.
0% was .68v and 100% (WOT) was 3.78v

2. Did full calibration as described on page one of this thread, and then checked TPS readings again.
0% was .69v and 100% (WOT) was 3.78v

3. Did partial calibration...twisted the throttle 0-50% twice, and then checked TPS readings again.
0% was .68v and 100% (WOT) was 3.78v

4. Did second partial calibration...twisted throttle 0-75% twice, and then checked TPS readings again.
0% was .68v and 100% (WOT) was 3.78v

Now, it should be noted that my 0% reading varies slightly between .66v and .69v depending on how hard I close the throttle. This is why aftermarket devices like the PCV have adjustable settings for 0% and 100%. Although the voltage readings of the individual TPS units will all be the same, the 'actual' closed and open throttle voltages will vary from bike to bike slightly due to throttle cable adjustments, idle settings, throttle body cleanliness? etc, etc.

I should also mention that my C14 is/was working perfectly fine...no complaints. It does display some throttle snatch, but I think this is pretty common with these FI set-ups. I think it has something to do with the transition from the IAP map to the TPS map, but that's just a guess based on where it happens on my particular bike.

I'm not saying that this TPS calibration doesn't work...but the numbers above show what my bike did before and after this procedure.

HTH,
Rem

Finally had a chance to read through everything...  Had a 200 mile round trip to Hood River for work yesterday.



Anyways, OK...

So Rembrandt, you have the KDS equipment. Good to know, and if you don't mind, I'm going to pick apart the test procedure a bit, and someone PLEASE tell me if my thinking on this is wrong. I'm not trying to insult anyones intelligence, but I am going to break this down Barney style to make sure we're working on common assumptions/ facts (if they are)

THE GLOWING LINES ARE THING'S I AM NOT 100% SURE ON. I WILL CHANGE/ UNGLOW THEM UPON CONFIRMATION.

The TPS, much like a volume knob on a guitar/ computer speakers/ etc, reads from 0%, to 100% (unless you are a kid in a garage band, then it goes to 11...). 

TPS:  (25-75% values determined with an interpolation calculator, for demonstration purposes only, these are NOT hard tested values.  0 and 100% values are tested per Rembrant using KDS above, may vary slightly between bikes)   

[CHART 1]   [THESE VALUES NEVER CHANGE EVER!]
TPS    0% = 0.68V
TPS  25% = 1.46V
TPS  50% = 2.23V
TPS  75% = 3.01V
TPS 100%= 3.78V

These TPS numbers represent 0% throttle opening, and 100% throttle opening. These Voltage numbers represent to the ECU how open the butterflies are. For the engine to run properly, the engineers have determined that it needs a certain air/ fuel mixture in the combustion chamber. The ECU reads the voltage from the TPS, and interpolates the Min/ Max voltages into percentages.  The ECU then takes this percentage, and tells the injectors to spray in the appropriate amount of fuel for that percentage of the throttle being open. The amount of fuel per volt is (from my understanding) hard-programmed into the ECU, and cannot be changed without flashing the ECU.  (At this point it goes from 'TPS throttle 0%', to the 'ECU throttle 0%' based on the voltage that the ECU is reading as 0%)

Now for all intensive purposes, lets say that the ECU tells the injectors to spray the following amounts of fuel per Volts: (FUEL CC's ARE MADE UP NUMBERS IN MY HEAD FOR DEMONSTRATION PURPOSES ONLY!!!)

[CHART 2]   [THESE VOLTAGES CAN CHANGE BASED ON THE CALIBRATION TO THE ECU. THE CC'S PER ECU PERCENTAGE NEVER CHANGES! (<<Edited to be correct info)
ECU     0% - 0.68V - 100CC
ECU   25% - 1.46V - 200CC
ECU   50% - 2.23V - 300CC
ECU   75% - 3.01V - 400CC
ECU 100% - 3.78V - 500CC


Now lets say you have an un-calibrated system.  For this demo we'll use TPS 25% TPS 100% (This is what I did in the video, by setting the throttle lock to ~25% and running the calibration.)  Now the ECU and TPS are mismatched.  The ECU see that when the throttle is fully closed (at idle), the TPS Voltage is 1.46V, therefore it needs to spray 100CC's of fuel in. (We know that in reality this is not the case, and that will be explained below)

[CHART 3]
ECU     0% - 1.46V - 100CC
ECU   25% - 2.04V - 200CC
ECU   50% - 2.62V - 300CC
ECU   75% - 3.20V - 400CC
ECU 100% - 3.78V - 500CC


The ECU is now programmed to see that when the throttle is fully closed (at idle), the TPS Voltage is 1.46V, Therefore it needs to spray 100CC's of fuel in.  Because it's a simple computer, it cannot detect a negative percentage. When you close the throttle completely, the ECU is putting out it's current amount of fuel for idle, set for TPS 25% (1.46V - 100CC), because according to the ECU's calibrated programming, TPS 25% = ECU 0%.  Remember, the ECU cannot read negative percentages, so if ECU 0% (idle) is 1.46V, when you go below that (to TPS 0%, TRUE idle) it still sprays 100CC's of fuel.  Now the bike is idling great. But as you open the throttle between TPS 0% and 25, it will still be spraying it's minimum 100CC's of fuel.  That is not NEARLY enough to satisfy the thirst of the cylinders when that much air is going in.  This costs lots of power, and can cause the bike to hickup, or even die. 

[CHART 4]

                             Correct
                             Fuel CC
TPS    0% = 0.68V  100CC    ECU OUT OF RANGE - 100CC   - LEAN CONDITION  (HESITATION OCCURS HERE due to insufficiant combustion)
TPS  25% = 1.46V  200CC    ECU     0% - 1.46V - 100CC    - A/F Mixture starts to finally increase (SPIKE IN RPMs OCCURS HERE)
TPS  50% = 2.23V  300CC    ECU   33% - 2.23V - 232CC    - Lean condition, less power, requiring slightly more throttle, using more fuel to maintain speed
TPS  75% = 3.01V  400CC    ECU   67% - 3.01V - 364CC    - Less lean condition, but still down on power, requiring slightly more throttle so on...
TPS 100%= 3.78V  500CC    ECU 100% - 3.78V - 500CC    - Proper A/F mixture





By properly calibrating the system, the ECU is reading the correct butterfly opening, therefore is putting the correct amount of fuel in. 


Again, someone correct me if I'm wrong in my thinking... I'm not an engineer.


[EDITED 23SEP2014 to have updated numbers and explanation regarding CHART 3 and 4]