R1200rt 2009 - throttle stuck on Max :-s

[HMMMYA]

Your comment on you mate dropping his rt and damaging his TPS which resulted in a 5k idle made me think I'd just get the TPS noted above since it's worth eliminating from the problem for £30.


I had 20mins to fiddle with the 02 sensors today and check the connector etc these appeared all ok.


The cyl 1 (rhs) which the GS 911 states is faulty I managed to remove. Looked. sooty which I'd imagine is normal, but nothing to comment really. The cyl 2 (LHS) I couldn't remove.


I disconnected the LHS and started the Bike. No change to problem idle speed. I then disconnected the RHS. No change to the problem idle speed either with both disconnected.


Ok I read somewhere these O2 sensors are of more importance when the bike is warmed up so likely not the main cause for my current.problem of idle speed but I will resolve none the less for the Improved running benefits.


The main area I don't really understand stand at the moment is why is RHS header pipe is so much cooler than my LHS even after 10secs of 5k idle. Do I have an additional problem on top of the TPS and O2 sensor or does the 02 sensor do more than I give it credit for? That said this temp difference was obvious even with both 02 sensors disconnected :-s If the main problem is the TPS why would this difference be felt across the two pipes? Tomo I'll likely pull the plugs and see if they tell me anything. Comments welcome. Thanks again.

[David.]

Your comment on you mate dropping his rt and damaging his TPS which resulted in a 5k idle made me think I'd just get the TPS noted above since it's worth eliminating from the problem for £30.

The quote was from the ukGSer thread, not a mate of mine, hope the new TPS does the trick.

[PeteM]

The main area I don't really understand stand at the moment is why is RHS header pipe is so much cooler than my LHS even after 10secs of 5k idle. Do I have an additional problem on top of the TPS and O2 sensor or does the 02 sensor do more than I give it credit for? That said this temp difference was obvious even with both 02 sensors disconnected :-s If the main problem is the TPS why would this difference be felt across the two pipes? Tomo I'll likely pull the plugs and see if they tell me anything. Comments welcome. Thanks again.

I would say that is almost certainly different fueling between the cylinders, lean burns are often a lot hotter

[David.]

I'll likely pull the plugs and see if they tell me anything.

A plug check is a good place to start when trying to diagnose fuelling problems.

This was two of four cylinders on my XJ650.


Left to right, #3 cylinder wasn't firing at idle, needed the pilot air screw adjusting.

I could grab hold of #3 header pipe, it was cold while the other three were hot.

[HMMMYA]

Looking at this thread, https://www.ukgser.com/forums/showthread.php/340637-How-to-fix-a-malfunctioning-Throttle-Position-Sensor the TPS may be u/s.

"It goes straight to 5000 revs which is exactly what happened to a friend of mine when he broke the TPS in a drop".

Finally found this quote, its a long feed. The comment below it, Makes a comment re catching the throttle cable under the tank when the fitting which can cause a high idle. It was the first time I've ever taken the tank of and put it on, so will need to check this as it's a simple one, I'd like to think I'd noticed but equally the tank had 20ltrs in it so it was awkward.

[HMMMYA]

And anothet one I didn't know about but will be performing. Sorry probably all basics but new to me.




[size=medium]BMW TPS Reset TPS reset routine: [/size][size=medium]1) Disconnect battery for about 30 seconds then reconnect (causes ECU to lose it's memory of Throttle Position Sensor). [/size][size=medium]2) Turn ignition to on but DO NOT start the engine. [/size][size=medium]3) Slowly wind the throttle fully open to fully shut, repeat this three times. [/size][size=medium]4) Turn off ignition. (ECU now stores TPS position data in memory). [/size][size=medium]5) Wait 5 seconds. [/size][size=medium]6) Turn on ignition again and start bike. Before doing this, I would check that the wiring to the TPS itself hasn't been kicked or disturbed, its the electrical unit on the air intake in front of your Left foot.[/size]

[David.]

The comment below it, makes a comment re catching the throttle cable under the tank when the fitting which can cause a high idle.

Likewise, when renewing the air filter, ensure that the right-hand throttle cable is not trapped by the underside of the air intake duct.

[David.]

Another one I didn't know about but will be performing.

When the battery went flat, was it removed from the bike for charging. If so, the ECU needs to re-register the throttle butterfly positions via the TPS. The Haynes manual describes the procedure similar to that posted above.

"Disconnecting the battery leads deletes all memorised settings (e.g. throttle position sensor). Loss of this information, could temporarily upset the running of the engine. Make sure the procedure is carried out before starting the engine."

When I changed the battery on my 2012 Camhead, I don't remember carrying out this procedure and the bike runs just fine.

I don't know that the TPS reset needs to be done routinely but a local BMW independent did it on my 2007 Hexhead when he made a home visit to check the valve clearances. I bet the BMW dealers don't do it.

[HMMMYA]

Ok finally got a new tps sensor on today then did a throttle calibration but no change. I was hoping it was going to be my silver bullet alas no. Status is therefore idling upto 5k when I start and when I disconnect the tps it drops to 1k.



Whilst I’ve been waiting for the tps I’ve done a few other jobs
New Sparks, old one were all consistent on both sides, sooty but nothing to fuss about.
02 sensors I pulled and went over the connectors for good measure and left to soak in injector cleaner over night. I also swapped them to see if the fault moved. There is lot of chat about this on the net with some people saying it helps and other saying it does bugger all. I cleanEd it for a punt. I no longer has a 02 sensor fault on no1 or no2. mayb something I did worked or I simply haven’t let it get to temperature. The temperature of each header pipe is no also consistent.


New air filter and good trickle charge on battery.


All cables are free and appear to work correctly.


Any ideas what could be my next port of call?


I was thinking about pulling the stepper motors, I tried previous but the bolts appeared seized so I left alone. Am I right in thinking these actually control the idle by referencing the tps?


Oh the TPS cost £28 from eBay and was a DELPHI SS10562-12B1 BMW (FA 09 236 156). Looks legit and not a dodgy copy.


Cheers


Duncan

[David.]

02 sensors I pulled and went over the connectors for good measure and left to soak in injector cleaner over night.

The Haynes manual says, "A contaminated sensor will send an inaccurate signal to the ECU, which should, in turn, illuminate the engine warning light in the instrument cluster. Do not attempt to clean the sensor - if it is contaminated, a new one will have to be fitted."

[David.]

Finally got a new TPS sensor on today.

Was the TPS position reset using the BMW diagnostic tester?

[HMMMYA]

Hi David, thanks for the comment. Re 02 I’ll have to wait and see what bother I’ve caused. So far the gs 911 and general display doesnt flag any faults not to say they won’t come. I’ve only been letting it run 10 secs at a time to not piss of the Neighbour’s with the high revs.


The TPS position was simply set using the 3x throttle twist procedure. I also used a idle synchronization option on the gs 911 which appeared to open and close the lh & rh TBs using the stepper motors several times before it said it was complete. Is there more to it? When I googled setting up tps some forum feeds suggested I just needed to do the 3x throttle twist procedureand that was it. I’m growing fonder of my k100 and it’s flat headed screw driver Idle adjustment.

[David.]

Status is therefore idling up to 5k when I start and when I disconnect the TPS it drops to 1k.

For the idle to be up to 5K RPM, surely the throttle body butterfly valves have got to be open more than is required for a 1K RPM idle speed. More air/fuel = more engine speed. My understanding is that the idle speed actuators (stepper motors) control the idle speed. If the throttle cables have been checked for the correct amount of free play, mechanically, these can't be causing the problem. So, back to the stepper motors, in this motorcycleinfo.co.uk guide to throttle body synchronisation, https://motorcycleinfo.co.uk/bmw-r1200g ... index12f4/ it shows the stepper motors being disconnected.

Has the vacuum at idle been checked on each throttle body (TB). How about removing the air ducts between the air filter box & TB's to physically see what position the butterfly valves are in before the engine is started. As above, for a 5K RPM engine speed, they must be open more than necessary.

I'm no expert on this, just trying to help. If it was my bike, I'd be taking it to a BMW dealer but then I have an insured warranty.

Here's an analogy, yesterday, I had the carburettor synchronisation checked on my 1980 Yamaha XJ650 an IL4 cylinder engine. The vacuum gauges were connected and the bike run at idle 1050 +/- 50 RPM. The throttle valve balances were spot on. The "mechanic" said the balance should also be checked at 4,000 RPM. This is not correct but what it demonstrated is that the idle speed can be increased by adjusting the throttle stop screw and opening the throttle valves without touching the throttle itself. Therefore, more air + more fuel = more engine speed.

[HMMMYA]

Hi David,


I found a bit more time today to tinker. I pulled of both stepper motors, behind the seals ie internally all seemed clean however sealing faces were all pretty crusty so clean all up and re installed.
I pulled the tank of one last time checking the routing again and removed the pulley in the splitter box so I can sense the feel of the each TB cable by hand. I reinstalled all after thinking it all felt fine.
I checked all the connectors under the tank and cable routes before placing the tank back on.
TPS 3x twist procedure
GS 911 - idle sync


Then started her and all was back to normal idling at 1150 :-)


Whilst it was running I plumbed in my carb tune out of interest. The LHS TB seem to have a significantly lower vacuum than the RHS. I didnt intend to tinker since I am aware I need to check the Valve clearances first but I couldn't help my self since they were out by so much. I tweaked the LHS 3 full turns CW i think. I did intend on bringing the LHS up the vacuum scale and the RHS down the scale but when trying to adjust the RHS the hex on the adjust thread sheared off due to corrosion and binding on the threads. I therefore balance the LHS to the RHS. I'm sure this is totally the wrong way to do it but if feels and sounds loads better.


I plan on doing the valve checks and then re addressing the TB balancing to text book as I'm keeping the plastics of for a bit since not been commuting with this covid malarky.


I took it for a spin round the block all felt good and then plugged in the gs 911. All codes are gone and everything appears good. I took a plot of the the 02 sensor readings whilst going through the rev range since it gave me the option, I want to read up on this and see if I can determine their condition from the graphs after my cleaning antics.


Thanks for your help, took a bit of time since life is busy and doing all on the street in 20 min slots often at night so not ideal for nice systematic posts. That I enjoy tinkering and its been good, learnt plenty and less daunted about getting all that plastic off for the next round of gremlins when they occur. The bike is unloved on the street all year round so corrosion is the biggy and there will be further corrosion related bother. All will be going back with plenty of grease on threads. Appreciate your patience. Cheers Duncan

[David.]

Thanks for the feedback, pleased you got there in the end.

Having done more than one thing at a time, it's probably very difficult to say what was causing the problem in the first place.