TPS voltage settings

[BrianR]

Superhypo

I did not mess up per say. When I had finished the bike ran really nicly, just used more fuel than a tractor. I messed and messed and finally ran out of time. My trip dictates I need good fuel economy. I have a twin max a accurate volt meter. I just got fed up with trying to get it spot on.

Went to CW in Dorchester and asked them to tell me where I was wrong. In all honesty I wasn’t a million miles out, just "out" enough to make it crap.

Anyway its running good now getting over 11 miles to the litre fully loaded (panniers, two up). Mind you I have also adjusted my riding style a bit.


I am leaving well alone and will never touch them again...never I tell you never..... I need beer

http://www.1a-2j.co.uk

BrianR

 

[(RIP) maverick]

I can add my tuppence here.

I set my TPS once on my 1100 to .371 the bike was never the same afterwards so much so the TPS basically stop working and it took a BMW dealer hours to find the problem and replace the item

The amount it will make a difference is neglible as Steptoe said better to just leave it alone. Well then again it is your bike and your money. Those TPS thingies is not that cheap I can assure you so please continue.........

 

[Steptoe]

Thanks Tim, so there is an optimum setting for it,

No there isn't an optimum setting It's just what Tim has found suited his bike and riding style.
Mine is set different to tims to suit me, as are others to suit them.

But the vast majority are not touched and run very happily.

Another thing to bare in mind is adjusting it to supposedly cure a problem, when all you could be doing is adding another equation to future diagnosis.

 

[Superhypo]

Went to CW in Dorchester and asked them to tell me where I was wrong. In all honesty I wasn’t a million miles out, just "out" enough to make it crap.
BrianR

Very curious what exactly did the guys from BMW to sort the problem? They set a different value of the TPS voltage, modified the throttle stop screw position or they had replaced something? How much is the tps voltage now?

 

[BrianR]

Superhypo

It was a combination of all sorts from TPS to end stop screws cable adjustment while taking CO2 readings then the acid test...... the test ride.

Whats the voltage now....... I dont give a flying feck.... i aint gonna look, it runs and im never....never i tell tyou ever going to touch them again.....

best left well alone and everytime you think you want to fiddle...... just go indoors and have a beer.

BrianR

 

[Superhypo]

Superhypo
everytime you think you want to fiddle...... just go indoors and have a beer.
BrianR

great piece of advice

 

[ktndwn]

Hi,

I needed to buy a new TPS sensor couple of weeks ago for my R1150GS Adv '02 and adjusted it to 0.36V. The sensor was broken and before the change the bike stalled with more throttle than, say, 10%. After the change it runs ok but surges still a lot.

Well, yesterday I took it to a local BMW-dealer for other repair. They said they had also adjusted the TPS - and said it runs much smoother now. (??)

Well, after I warmed the bike with a 100km trip and let it idle.. it fluctuates between 800-1300 rpms. What the f***?

I checked the voltage and it stated 1.06V!

Did I do the adjustment wrong or what? I've read that the voltage should be around 0.3-0.4 volts.

 

[Thinc2]

don't get dragged into doing the whole "zero zero" thing where you reset the throttle stops. these are set at the factory using a flow bench and are best left alone.

just check the voltage from the TPS to earth and rotate the TPS unit to adjust. it's a five minute job.

+1000

 

[Thinc2]

Hi,

I needed to buy a new TPS sensor couple of weeks ago for my R1150GS Adv '02 and adjusted it to 0.36V. The sensor was broken and before the change the bike stalled with more throttle than, say, 10%. After the change it runs ok but surges still a lot.

Well, yesterday I took it to a local BMW-dealer for other repair. They said they had also adjusted the TPS - and said it runs much smoother now. (??)

Well, after I warmed the bike with a 100km trip and let it idle.. it fluctuates between 800-1300 rpms. What the f***?

I checked the voltage and it stated 1.06V!

Did I do the adjustment wrong or what? I've read that the voltage should be around 0.3-0.4 volts.

I had an 02 1150GS when I was in the US and it surged badly. I could tune out most, but not all of the surging by having the valves spot on and carefully synched with each other, and by having the TPS very carefully adjusted to 0.385 - 0.39. I had very few issues with my valves, but if my TPS fell even to 0.36 or so, I had significantly more surging. I can't explain why, but there was a clear correlation.

I now have another 02 GS - it doesn't surge and I've never adjusted the TPS as a result. (although I've checked to make sure it is relatively in the right range).

 

[Trullion]

I have adjusted the TPS on both my bikes. The first time I did it was to cure rich running on my 850GS. I had already replaced the potentiometer (neither of my bikes has a cat) because adjusting it made no difference. (The pot adjusts the CO2 level in the exhaust gas at tickover and low throttle opening). I also replaced the oil temperature sensor. Together these helped with the rich running, but did not fully cure it. This is why I adjusted the TPS setting to 371mv. This actually cured the rich running on my 850. Flushed with this success I then adjusted the TPS on my 1100RS to the same setting. Whilst it didn't affect the running at all, it did richen the mixture so I put it back to the original setting.

From my own empirical research I believe that for those bikes with a pot the TPS setting simply determines the point at which the TPS assumes control of the mixture strength from the pot. This is why adjusting the setting correctly can be beneficial in curing surging as there is a seamless transition from one to the other. The TPS itself is simply another potentiometer, sending an increasing voltage to the moronic unit as the throttle is opened, causing more fuel to be supplied to the injectors.

I have never used the zero=zero procedure because as far as I can see it has nothing to do with adjusting the TPS and fiddling with it is likely to introduce a very unwlecome new variable into the equation.

Whilst the voltage of 371mv suits my 850, it makes my 1100 run rich. I don't believe that there is a universal optimum voltage; the best setting is unique to each bike.

My advice (FWIW) is to leave it alone if the bike runs ok and to adjust it only when the more likely culprits have been eliminated. Dunno about bikes with cats, or the 1150s. And whatever you do don't follow the zero=zero procedure unless you really want to risk scr*wing things up.

All the above could well be complete and utter b*llocks. All I know is that neither of my bikes surges nor runs rich and that a bit of judicious adjustment of the TPS voltage setting can be beneficial.

Take care.