Hi everybody,
I believe that the throttle position switch should click when the throttle is closed but mine doesn't! there appears to be a different throttle position switch on bikes up to 1992. Does the later (1993 on) switch click or not? The fuel system is Motronic. The later switch is at least double the price of the early one. Your help would be appreciated as I only have a Haynes manual which covers up to 1992. Thanks

As I understand it, the Motronic uses a variable resistor, a slide system to vary voltage (I assume) so that the CPU (yes Motronic is a computer) can read the precise position of the throttle. Someone has posted a pic of an internals of this recently.

The L-Jetronic system uses a two position microswitch arrangement (thus it clicks) to tell the electronics if the throttle is closed or fully open. L-Jet is not a computerised system, it is simply an analogue electronic box.

I've seen the two switches at around 45 GBP on one of the UK sites.

The thing is that you don't need the TPS (the microswitch kind) at all, but you must have the variable resistor to make the bike run.

Thanks for that information. Does anybody know how to set the TPS (as there is no click) position as I am suffering backfiring on over run.

redbeemer wrote:Thanks for that information. Does anybody know how to set the TPS (as there is no click) position as I am suffering backfiring on over run.

Sorry, it appears that no one provided instructions. Ok try this:

• remove the coil cover (box just behind the motor) to get batter access to the TPS screws.
  
• There are two screw on the TPS body, loosen both and finger tighten them to hold the TPS without assistance.
  
• slowly rotate the TPS towards you with the throttle fully closed. Now rock it back and forth.
  
• You should hear a click each time. adjust the thing so that it clicks as you rotate it towards you and lock the TPS in place.
  
• if you got it right, you should hear a click each time the throttle just cracks open (and then again when it closes).
  

Now for the final test: open the throttle slowly. As you crack it there is a click. Keep winding the handle until at full throttle. Just before you get there you should hear another click. That tells the EFI to squirt extra fuel in.
Done.

Ned,
Interesting to note he experiences backfire what?
Ajays

I don't have experience with the Motronic system, but believe that you won't hear a "click". On the Motronic, the TPS is a potentiometer.
I may be wrong, but if anybody wants to give me a 16v to enjoy the ride before testing it, I will give you a definitive answer

oops, my fault ... please ignore what I said... Motronic is not adjusted as I described above.
In fact I already made that comment in my original post earlier

Thank you Bert

There is no "click" on the tps for the models after 1993. The way to check it is using the connector with 3 pins under the seat. You put a voltmeter between plugs 1 and 3 and without throttle you ought to have 12Volts, and nothing as soon as you moove the accelerator... if not, you must change the position of the tps till you get that.

and Bert, if you come to France that summer, i'll let you try the K11, so you'll know what the 4valves are

Hi redbeemer,
The 16 valve has no micro-switches in the in the throttle position sensing unit it is a variable resistor and it is set using the BMW diagnostic tool MA 2.1 or MA 2.2 I shall look to see if there is an alternative method

Hi Everybody,
Thanks for all your advice but I managed to get hold of a piece of equipment called a PW Sytemtest V.2.0 from ebay for approx £30.00. This tests the motronic and ABS system, enables you to read and reset the codes. It also sets the throttle position switch! It works very well.
I have contacted the person who was selling them but he has none left and is not getting any more.

Thanks for the information.

At least people with the 4 valves engine know what to look for.

green cat wrote:There is no "click" on the tps for the models after 1993. The way to check it is using the connector with 3 pins under the seat. You put a voltmeter between plugs 1 and 3 and without throttle you ought to have 12Volts, and nothing as soon as you moove the accelerator... if not, you must change the position of the tps till you get that.

So, as soon as I start to open the throttle I should see, 12V, zero, then a gradual increase in the readout, right?

No, eh maybe......:-)

It is a variable resistor or potentiometer. The ECU needs to see a certain resistance when the butterfly valves are closed. It will then adjust accordingly. I wonder about the above as, it being a potmeter, it should gradually change without some sort of 'switch-working' re 12V on/off.

Although this is for a 1100 I think it is the same set-up here.

Before adjusting the TPS it is important to ensure that the throttle cable is adjusted properly so the butterfly plates are closed fully. Our biggest challenge is all the muppets before us who owned or fiddled with the bike before we got it. There are a number of inviting screws and adjusters all of which cry out to them "adjust me adjust me it might make it smoother, faster, quicker go on do it". And they cannot resist, sometime later we all come along and try to adjust it all back to base setting. I came across some stuff from the late great Rob Lentini on setting up late version oilhead TPS's and I need to research if that is applicable to ours.
Regards,
K-BIKE

Yup, I got one of them. (8-((

K-BIKE wrote: I came across some stuff from the late great Rob Lentini on setting up late version oilhead TPS's and I need to research if that is applicable to ours. K-BIKE

Nice to see the name of Rob Lentini mentioned here. He was a great mentor and educator!

Hey K,

Keep us posted on what you discover from your cross check. All my new cables just arrived from Motobins and got the tank off and I'm about to dive in so any bits of wisdom from Mr. Lentini would be greatly appreciated!

J

Hi Folks,
I got the following information from http://www.k11og.org/forum/viewtopic.php?t=2110&postdays=0&postorder=asc&start=0.

This is for Motronic 2.2 but 2.1 may well be the same
There is a black 3 pin diagnostic connector on the left side of the bike above and to the left of the battery, you will need to remove the side cover to gain access. This connector will have a blue plastic weather protector connected to the open end. Pin #1 will have two Brown/Black wires, Pin #2 will have one Brown/White wire and Pin #3 one Brown/Green wire. Here are the pin functions for this diagnostic connector.

Pin1: Motronic Diagnostic Fault Code Read-Out and Fan Test Activation
Pin2: ABS Diagnostic Fault Code Read-Out and RESET
Pin3: Motronic Diagnostic Activation of the Throttle Position Sensor Test.

Motronic Fault Code Readout:
Connect a common 12V LED (One acceptable LED is a Radio Shack Red LED P/N 276-270)
to pin #1 (+lead to Battery + , -lead to Pin#1). The LED is not necessary for K-bikes, the temperature warning lamp to the lower right of the tachometer will flash the diagnostic codes.
NOTE: When performing this test on an Oilhead you will need the LED since there is no temperature warning lamp.
Turn the ignition ON and short pin #1 on this connector to ground for 5 seconds, the temperature warning lamp near the tachometer will flash in unison with the test LED you have connected above. The temperature warning lamp and the LED will illuminate solid for about 2.5 seconds, then a give a number of short flashes, count the short flashes. This flash-count is the first digit of the stored fault code. Approximately 2.5 seconds of no light follows the first count, then it will flash the second count (second fault code digit) and this is repeated for the third and fourth count. This repeats until you turn the ignition off. The beginning of each fault code display sequence will be indicated by the 2.5 seconds of solid on of the temperature warning lamp and/or the Test LED.

NOTE: The Motronic Control Unit only displays 1 fault code at a time (4 digits) even if there are multiple faults. Once the first displayed fault has been recorded, repeat the Ignition OFF, Ignition ON and ground pin #1 for 5 seconds to display the next stored fault code.
Continue resolving faults until "4444" is displayed indicating all faults have been resolved.

NOTE: 1122 and 1133 faults can be spurious in nature. If either of these codes appear and you do NOT suspect a Hall Sensor problem, (In other words, you are NOT diagnosing a no-start condition), crank the engine for a few seconds and the Hall Sensor fault codes should clear. You will have a 4444 code which indicates No Faults Stored.

Code Fault
1111 CO potentiometer not detected with Oxygen sensor disconnected
1122 No signal from Hall Sensor #1 (Upper or TDC Sensor, Coil 1/4)
1133 No signal from Hall Sensor #2 (Lower or 180° Sensor, Coil 2/3)
1215 Throttle Position Sensor out of range
1223 Water Temperature Sensor out of range
1224 Air temperature Sensor out of range
2341 Oxygen sensor at limit
2342 Oxygen sensor signal invalid
2343 Mixture setting at limit
2344 Oxygen sensor shorted to ground
2345 Oxygen sensor shorted to 12V
3333 Fan Test in Progress (the fan motor will run intermittently and the 3333 code will flash)
4444 No fault stored


Throttle Position Sensor (TPS) Test:
To test the TPS
Ignition OFF, Ground Pin #3 and monitor Pin #1 with a 12V LED (+lead to Battery + and -lead to Pin#1). Ignition ON, Engine OFF (Pin #3 should remain grounded during this test)
The Test LED will be ON at idle (closed throttle) and OFF just above idle. You should also be able to watch the temperature warning lamp on the tachometer blink ON at idle and OFF just above idle.
Pin #1 should be Low at idle and High just above idle. In other words, if you are measuring from ground to Pin #1 with a voltmeter, Idle should be close to 0 Volts and just above Idle should be close to 12 Volts. (This test also works for Oilheads (1994-2001) with Motronic 2.2 Engine control Units but since there is no temperature warning lamp, you must use either a voltmeter or a Test LED as described above).

NOTE: Measuring the voltage between pins 1 and 4 at the TPS connector should indicate
0.375 Volts at the idle setting (closed throttle) with ignition ON engine OFF.
Snap the throttle open/closed a few times to ensure a consistent reading. To adjust the TPS, loosen the two screws slightly and rotate the TPS until the temperature warning lamp (or the Test LED) 'just' comes ON at idle and goes OFF just above idle. If you are using a voltmeter, adjust the voltage to 0.375 at idle (closed throttle). This voltage MUST remain below 0.400 Volts at idle.
Regards,
K-BIKE

Many, many thanks for taking the trouble to post that K-BIKE. It's a real help. (nick,hereford,UK)

CF, could we make that a sticky or post it on the info site?

ReneZ wrote:CF, could we make that a sticky or post it on the info site?

Good idea Renez. This document is now posted (PDF format) in the download section.