• Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

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    Thanks for your patience and support!

TE 511 EFI - Adjustable Sensors?

It is to set the TPS to the desired voltage output at idle which on your typical Keihin setup is .5v at idle with safe range of .4-.6v. Tweaking the TPS a tad is the easiest way to richen or lean the whole map. Making the ECM think the throttle plate is open a bit more than it really is, will cause richer delivery. IE setting it at .6vdc at idle will be richer than setting it at .4Vdc. Of course it is rare that a machine needs linear change across the board to make it run better esp when adding pipes etc. That is where the fuel tuners are usefull that separate the map into many pieces or at least low, mid, high.
 
Thanks Marc for taking the time to share your EFI knowledge, I liked the thread on Altitude Adjustment......now I can really screw up my machine:eek: Does adjusting the pressure sensor offset the fuel map linearly also?

My bike won't run for more than about 1 sec on the first cold start. I have a JD tuner and have the idle adjustment (blue/green) leaned all the way out to get to it running on the 2nd cold start (used to take 4 starts). Is this normal?:banghead: Does the JD tuner change the resistance at different points (Idle, low, mid, high, etc)? So, do I need to unplug the tuner and measure Vdc at sensors? Also, my bike has 2 TPS's. Why is that?

I have a 2007 yamaha raptor quad (with much simplier looking Mikuni FI) that has tons more hours on it and has always run on the first start (also has never had flame outs or any other engine issues).
 
Again I have not owned an EFI husky, mikuni or keihin. I do spend much of my 50hr workweek working on EFI of all kinds in many brands, though.

If the TPS has slotted mounting points you would loosen the screws and move it one way or the other. The goal is to LOWER the output voltage at a given throttle position, making the ECM think the throttle is several percent more closed than it really is.

I would hate for anything I post to result in someone's bike running WORSE and without it in front of me, or a service manual with wire diagram to look at, I simply cannot give you a precise answer. The short answer is , yes, tweaking the TPS can make it run leaner. Doing it wrong could make it worse, and even putting marks on the body, it can be difficult to return to where you just were.

If you are at wits end with the bike, place some marks on the TPS and Throttle body to mark roughly where it is and to use as a movement gauge. The tps is in line with the throttleplate shaft. Tweak the tps A LITTLE in the SAME direction that the throttle shaft moves when you open the throttle. Does that make sense? Ride it, decide if it improved it, and go from there.
 
SDPUTTER said:
Does adjusting the pressure sensor offset the fuel map linearly also? Yes but is difficult to aachieve and not really practical

My bike won't run for more than about 1 sec on the first cold start. I have a JD tuner and have the idle adjustment (blue/green) leaned all the way out to get to it running on the 2nd cold start (used to take 4 starts). Is this normal?:banghead:

I'm not sure.

Does the JD tuner change the resistance at different points (Idle, low, mid, high, etc)?

No a JD doesn't get a TPS input. like other tuners it varies the pulsewidth (length of time the injector stays "on"). It does so through some complicated algorithms I presume, with no TPS input.

So, do I need to unplug the tuner and measure Vdc at sensors?

I would look at the coolant temp sensor on the cylinder or head. It should measure 2.8-3.0 volts at 70degf. More if colder, voltage drops with temperature. A good way to evaluate it is to compare it to the Intake Air Temp sensor in the airbox or airboot. They should read the same on a cold motor. The JD won't affect this. It is possible that all is fine and other factors cause the starting characteristics. Especially if it seems to run fine when warmed up.

Also, my bike has 2 TPS's. Why is that?).

I've never seen that. One is likely the MAP or manifold absolute pressure sensor, or an IAC idle-air control valve. If it has two throttle-plates one in the middle and one at the air side, the airside is a secondary throttle valve controlled by a motor, and would have a TPS style sensor to varify it's position to the ECM which may be identicle to the TPS, the TPS is ALWAYS in line with the main butterfly throttleshaft.
Click to expand...
 
Awesome Marc! What your saying makes total sense to me after reading about (what I think) are very slight differences in fueling between peoples bikes......

Apparently the TE has 2 TPS's according to the shop manual. I accidently/on-purpose removed "Throttle Sensor #2" which appeared to fit over the end of a shaft that moved kind of freely. I thought it odd that the shaft moved independant of twisting the throttle, but now makes sense with your info. My first attempt at reinstall obviously was not right and the bike idled real high and would not come down. After my 2nd attempt the bike ran fine. So it sounds like if you wanted to tweak your fuel delivery across the board (linearly), tweak the 1st Throttle Sensor on the main butterfly? All the sensors have a painted mark from the factory that makes it easy to get back to the factory setting (maybe put there for idiots like me:D).

It also apparently has a MAP sensor. I'm thinking it is heavily guarded in the front of the throttle body, with a different style adjustor. Shop manual didn't show a picture, but it was called out in the wiring diagram........Note to self: DONT TOUCH.

For my cold starting issue, I'm going to try an Iridium plug first before I pull the sledge hammer out to fine tune now that I'm dangerous with more knowledge!
 
MotoMarc36 said:
.... Tweak the tps A LITTLE in the SAME direction that the throttle shaft moves when you open the throttle. Does that make sense? Ride it, decide if it improved it, and go from there.
Click to expand...

Awesome stuff Marc, no problems on your responsibility, it's my bike, all on me, I appreciate the tip and am going out to start tweaking now!
 
Awesome guys hope the info helps, feel free to ask questions or PM as needed. I'm certainly not the end-all on EFI but I have learned a lot over the years and at various OEM training classes (Honda's was amazing....) and am always willing to share knowledge!:thumbsup:

SDPUTTER said:
So it sounds like if you wanted to tweak your fuel delivery across the board (linearly), tweak the 1st Throttle Sensor on the main butterfly?

Correct. In thinking more about it I have heard of TPS reset procedure on these 449/511's that involves disconnectiong the battery etc. Not sure if it works, but if it does, it MAY undo your tweak and recalibrate the ECM to see the higher tweaked TPS voltage as the "new" closed-throttle base voltage and make your tweak null.

All the sensors have a painted mark from the factory that makes it easy to get back to the factory setting (maybe put there for idiots like me:D).

Cool. Yes they are also there to help us mechanics decide if a sensor has been tampered with from new, if the paint is broken it can indicate a need for attention. As you found, they can be installed improperly.


It also apparently has a MAP sensor. I'm thinking it is heavily guarded in the front of the throttle body, with a different style adjustor.

Yes Keihin often integrates it right on the throttle body, a neat setup. On these FI setups the MAP acts as a BARO sensor at startup, and tells the ECM what the ambient barometric value is, then it reverts to a Manifold Absolute Pressure sensor when the motor is running. So, if your ride takes you 4000 feet higher, it may be necessary to shut the bike down for a few seconds, then fire it back up to allow the map to give the ECM an updated BARO reading.

Note to self:. DONT TOUCH

Yes Solid advice and no need to touch it!!

For my cold starting issue, I'm going to try an Iridium plug first before I pull the sledge hammer out to fine tune now that I'm dangerous with more knowledge!

Good call, I've heard that it does help!
Click to expand...
 
SDPUTTER said:
My bike won't run for more than about 1 sec on the first cold start. I have a JD tuner and have the idle adjustment (blue/green) leaned all the way out to get to it running on the 2nd cold start (used to take 4 starts). Is this normal?:banghead:
Click to expand...

My TE511 with uncorked exhaust and JD tuner always take three tries when cold in the morning. Did it when completely stock too. Does not bother me as i let it idle a good 2-4 minutes before riding off anyway. Many people say with EFI let it start and run for a good minute or two before touching the throttle at all. this lets the TPS and learning part start clean.
 
Motosportz said:
My TE511 with uncorked exhaust and JD tuner always take three tries when cold in the morning. Did it when completely stock too. Does not bother me as i let it idle a good 2-4 minutes before riding off anyway. Many people say with EFI let it start and run for a good minute or two before touching the throttle at all. this lets the TPS and learning part start clean.
Click to expand...
Mine (smr 511) is fuel injected and it takes between 2-4 starts cold in the morning I just always thought it was normal
 
http://www.cafehusky.com/threads/2011-te449-running-well-with-factory-efi-system-finally.41069/

MotoMarc36 said:
It is to set the TPS to the desired voltage output at idle which on your typical Keihin setup is .5v at idle with safe range of .4-.6v. Tweaking the TPS a tad is the easiest way to richen or lean the whole map. Making the ECM think the throttle plate is open a bit more than it really is, will cause richer delivery. IE setting it at .6vdc at idle will be richer than setting it at .4Vdc. Of course it is rare that a machine needs linear change across the board to make it run better esp when adding pipes etc. That is where the fuel tuners are usefull that separate the map into many pieces or at least low, mid, high.
Click to expand...

The Factory setting for the TE449 TPS is 0.7v.
Most are much less than that, closer to the high 0.5v range.
Mine runs quite well at 0.8v, it stopped the flameouts and stalling without the need for a PCV or Jd tuner box.
I've linked to the thread above.
 
Hi,
Sorry for replying that old topic.
First, thank you all for sharing your knowledge and experience!
Am I correct: to tweak the TPS sensor enrichens the injection, since the ECU believes that the throttle is more open?
Second point: There is a TPS reset, where the ECU learns the min (and max) value of the TPS sensor.
What happens now when you perform a TPS reset after the TPS sensor tweak?
If I understood everything correct, it would be like without the tweak and the reset? Is this correct?

PS: the voltage on my TE449 is 0,71 V originally. If you do not have the mentioned adapter, it is quite easy to put some small rigid cables into the connector of the ECU from outside after removing the cap there.

BR Florian
 
As mentioned, changing the TPS position does alter the AFR across the board but it's not linear from a percentage standpoint. Think about it, altering the TPS to tell the system that the throttle is at x% (degrees) open instead of the actual physical y% open (say a difference of +\-5 degrees) makes a huge difference at lower throttle positions and less at more open positions. For example, at the actual physical opening of say 10 degrees, a 5 degree difference is 50 %! and the system will enrich or lean the mixture accordingly. At 95% actual position the same 5 degree difference is only about 5%! Actual air flow vs throttle opening is not linear as well, being biased towards lower openings (the % change in flow is greater at lower openings), but not nearly enough to change the relationship as described. Conclusion, changes in TPS significantly affect lower throttle openings the most and taper off as the throttle is opened based on the percent change. Of course, I'm assuming a system where TP and RPM are the main variables for the fuel map. Some systems use the MAP sensor for load along with RPM to define the fuel map and the TPS mainly for accel fuel and fuel trim under certain conditions.
 
Hi,

Thanks a lot for your answer and for highlighting the drawbacks/specialties of tweaking the TPSensor.
Maybe my questions was not clear: what happens if you perform a TPS reset (intended or unintended) of the tweaked system? Will it become untweaked by the reset process, because it learns the initial positions again?

BR Florian
 
Tweeting the TPS position followed by a reset of the closed and full open positions should essentially recalibrate the system to the stock settings. If you want to bias the the fuel ratio, resetting after altering the TPS position will cancel any desired affects as it'll normalize any voltage offsets. On other non adjustable TPS systems, the only means to create a delta offset is through a software change (reset) along with changes in the mechanical closed throttle stop screw.
 
Hi,

thanks for confirming my guess.
Then I wonder why some of us chase absolute values (stock 0,7; running well at 0,8; some bikes down to 0,5) and - if I understand correctly - do TPS reset more of less regularly. Then the absolute value should not be important.

In other threads people report that they need a TPS reset every few weeks to keep the bike running properly.
Does anybody know why? I guess possibilities are
-drift of 5V reference of ECU (unlikely)
-GND shift (may be, if I remember correctly, the TPS ground was not same as battery ground in my measurement)
-changing resistance in connectors (hopefully not)
-change/drift of the TPS sensor itself (does anybody know what's inside? Simple potentiometer or magnetical/optical encoder?)

@Dangermouse: please do not get me wrong. I appreciate your pioneer work on easy tweaking the system. I just want to understand the whole thing. Sorry, I'm engineer ;-)

BR
Florian
 
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