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Need throttle position sensor!

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Pavel, do you know how to use an analog or digital volt/ohmeter ?

 

Me? Not really, but a friend of mine who fixes german cars for living should know, I guess:)

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It sounds like a few tweaks have crept in. Creeping to 6th with idle throttle. Wow.

 

You should go back and do the TPS calibration from scratch. Make sure the air bleed screws are set. I use 2 turns out.

Set the idle to 1200 when warm. Anything lower and you risk the stalls.

 

Will be on it again this weekend - thanks for useful tips.

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I'm with Cliff, you measured the voltage on the wrong wire. 5 volts is the supply voltage. If you read that on the sensor wire (what is read by the ECU) it would think you were beyond wide open all the time. I also doubt it would run for long, if at all. Think fouled plugs.

 

If the TPS is really "shorted" you will have 2 wires with 5volts and the third should be the ground, otherwise measure again.

 

I have seen TPS short high but never past 4.5 volts or so, if the ground wire has resistance it will push the TPS signal high, but never to the full 5volts.

 

Why didn't you take the bike back and have them take it for a test ride. :whistle:

 

Normally a rich mixture will cause idle speeds to drop quickly, sometimes even die on closed throttle. Lean mixtures (think air leak) will cause the idle to hang high durinng closed throttle, which will get worse as the bike get even hotter from the lean mixture.

 

We measured the voltage for the whole afternoon, all possible combinations among all the three wires, TPS in place, TPS taken out of the TB but connected (in this case the different positions made by rotating the TPS manually), slider only after disconnecting from TPS. We used digital voltmeter. Results: two wires with 5V or -5V regardless of what we did with TPS, one wire with nothing.

 

I did not take the bike back because I was leaving the country for three months, have other bikes which I ride instead and have more important things to do on Sat morning. I was also extremely angry with other aspects of this service (like brand new paintjob mysteriously scratched on two places while the bike was at the shop, cylinder oil leaks and so - I just did not want to argue with people - one reason I went to this shop was their reputation - some of a cold shower to my experience:) But that's okay.

 

If there is an airleak why the problems disappear completely (together with idle:) when the throttle butterflies are set fully closed at idle?

 

But anyway - will have the new TPS for weekend - hopefully we shall see the light at the and of the tunnel:)

 

Really appreciate the advices.

 

Pavel

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Do not know, they said they've cleaned and repositioned it - assuming you have to take it out for cleaning.

 

The TPS is a very simple device, just like the volume control in a radio.

You may be measuring the voltage on the wrong wire

One is allways +5, another is allways zero, the third wire Voltage varies in between, with the throttle opening.

If you look at the ECU plug the wire going to pin 11 is the one to monitor, slice a little insulation off it and

measure from there to ground. Another way is to drive a dress pin thru the wire and connect your meter to that

 

We did the measurements among all the 3 wires, all possible combinations, using a digital voltmeter - two wires do 5V regardless of slider position, one is nothing. We used tiny dress pins to punch through the insulation. What do you make of this? Will have new TPS on weekend - we shall see.

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We measured the voltage for whole afternoon, all possible combinations among all the three wires, TPS in place, TPS taken out of the TB but connected (in this case the different positions made by rotating the TPS manually), slider only after disconnecting from TPS. We used digital voltmeter. Results: two wires with 5V regardless of what we did with TPS, one wire with nothing.

 

 

I think your TPS has an open circuit at the end normally grounded. I don't know how that would happen unless they wound it too far backwards perhaps.

 

If you pull it off it should measure 3000-5000 Ohms between two wires no matter where you turn it and it should change from 0 to maximun between each one of the previous two and the third wire.

If you have one wire with no connection at all its screwed I'm afraid.

 

Heres the link to setting it

http://www.v11lemans.com/forums/index.php?showtopic=12204

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We measured the voltage for whole afternoon, all possible combinations among all the three wires, TPS in place, TPS taken out of the TB but connected (in this case the different positions made by rotating the TPS manually), slider only after disconnecting from TPS. We used digital voltmeter. Results: two wires with 5V regardless of what we did with TPS, one wire with nothing.

 

 

I think your TPS has an open circuit at the end normally grounded. I don't know how that would happen unless they wound it too far backwards perhaps.

 

If you pull it off it should measure 3000-5000 Ohms between two wires no matter where you turn it and it should change from 0 to maximun between each one of the previous two and the third wire.

If you have one wire with no connection at all its screwed I'm afraid.

 

Do you mean the TPS is shorted somehow?

 

Heres the link to setting it

http://www.v11lemans.com/forums/index.php?showtopic=12204

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No, one end is open. The wire that is grounded should hold one end of the pot at zero and the slider is supposed to measure from zero to 5 Volts.

Because the ground end is open the whole length of the slidewire is at 5 Volts.

 

Bad TPS.pdf

 

ECU Test Points.pdf

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Seems it’s mounting has been altered and is no longer mechanically adjustable.

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