High idle speed.

[Rugged Path]

I replaced the bushings on the two TB’s of my 02 1150GSA due to excessive clacking noises. All reassembled and fitted back with the TPS installed roughly to it’s original position (from photo).
Started up OK but, idling close to 3,000 rpm.
I slackened off the throttle stop screws and made sure there was slack in the cables to see if it could be reduced but it didn’t.

Would small adjustments to the TPS either way reduce the idling speed or is there something else?

Does this ‘throttle positioning sensor’ need to be somehow calibrated with the ECU?

When reassembled, the butterfly disc snapped shut on both and the shaft springs positioned correctly.

And just to say, the clacking noise has stopped without replacing the expensive shafts.

Thanks.



Patria o Muerte

 

[DrFarkoff]

F F S Adjusted throttle stop screws? The ones at the inner sides of the throttle bodies? They are factory set

If you have any chance to reset those throttle screws to where they were do it now before you forget or lose the patina of where they were

............

Did you touch the big brass screws ?

Did you correctly seat the throttle bodies in the inlets?

Are the inlets manifolds sealed correctly?


I had to sort this for a bloke who did the same and it takes a while

.............................................

The TPS should be set to Zero point 38 to zero point 4

You connect the red wire to the rearmost wire in the plug and the black wire to a GOOD ground

you are looking that it should read as 0.375 :~ 0.395 in the 20 Volt DC range

 

[Rugged Path]

1. Did not touch the big screws.
2. TB’s seated well in the rubber inlets to cylinder and tightened.
3. The plastic inlet ducts seated well into the bodies and no kink. Jubilee clips tightened.

Will readjust the throttle stop screws to original setting as best I can.



Patria o Muerte

 

[DrFarkoff]

Did I read somewhere about being able to fit the butterflies upside down ??? They are slightly eccentric?

About the throttle stops, How I did it was

With the throttle bodies off the bike, use a 1mm drill bit so that the butterfly just stops it being easily withdrawn from the lower side

Get the bike up and running and go for a ride

Screw the big brass screws in/out if the idle is high/low just so you can manage a ride out for 20 mins to get the motor to working temp

AS soon as I came back in I would check the TPS was set to about 0.38 volt Ign on but engine not running

then start the motor and you are looking an idle speed of about 1050 rpm plus or minus 50 rpm @5 bars on the Rider info display

If it idles at abut 850 to 900 when you have screwed the big brass screws all the way in You are actually not that far off

Check throttle cable balance for an even acceleration (leave that 1.5 to 2 mm free play in both just at the adjusting collars)

Then back the Big Brass screws out hopefully about 2 and a half turns out "ish" will see you about 1050 ish rpm again

If its like half a dozen turns ...

Screw the big brass screws back in and screw the throttle stops half a turn in (clockwise) then quickly Recheck TPS is still in spec (You do this to make sure that the motor is not running too weak or too rich which would screw up your throttle setting procedure You can leave it attached and switched on it will do no harm but stop the motor for taking a reading )

And start up again

IDEALLY you want

0.38 on TPS
2 turns out on BBS
Balance (Approx) across the two throttles at idle and when you twist the throttle
Idle speed at 5 bars of 1050rpm + or - 50rpm

It takes a while to set the stuff up My main advice is

Don't walk off with the engine running (believe me its easy to be distracted!) Also prevent CO poisoning, open the door (s) I work outdoors when running the engine, it also helps to keep it cooler

Keep an eye on the engine temp If its going 6 bars or up it affects your fuelling Get a big fan out or a couple and try and keep it around 5 bars

If you can have everything you need sitting on a table or bench beside you You really do want to get this done as quickly as possible to keep the motor temp in spec

Good Luck

Edit I didn;t mention above If you can't get the Idle down enough with the big brassscrews in all the way and cables slack when its at 5 bars screw the throttle stops out 1/2 a turn and check TPS etc

Try and maintain balance across the throttle bodies with the big brass screws all the way in when you are adjusting

If I recall correctly a flexible shaft 7mm socket screwdriver made the job much much easier when trying to adjust the throttle stops with the engine running

 

[Rugged Path]

I marked the butterflies A air and F fuel side. Did each TB separately.
Never checked the TPS using a multimeter so, need to find a video to get an understanding what to do.

Once it is running ‘fairly’ smoothly, I’ll get it serviced by a local indie bmw mechanic.



Patria o Muerte

 

[DrFarkoff]

Never checked the TPS using a multimeter so, need to find a video to get an understanding what to do.

Basically you pull the rubber boot downwards at the connector so you can see the wires

you can use a paperclip pushed up into the rearmost connection (I prefer to BackProbe rather than push a pin into the wiring)

You connect the positive of your Multimeter to here and the negative goes to a Good known earth The only issue with this is how accurate your multimeter is? If the internal battery is knackered or its just out of whack I had a couple do this and binned them and bought a cheapie at the local DIY store

One that has crocodile clips is a good choice

Set to the 20V DC range and switch the ignition on If you have no reading check you have the paperclip correctly touching the rear wire (Red or red/white depending on year but always the rear most wire) and a good earth I use battery earth

You are looking for a value of 0.38 v If it is above or below you slacken the small screws "just" so you can move it VERY SLIGHTLY It can go off scale quickly so a small mark for your start position is a good idea

a Small rotation either way can make a large change once you find the desired value just "snug" the screws they are only tiny so its from loose from the point when you have to apply ANY pressure just one eighth of a turn should be sufficient a tippex "witness mark" is good in case you knock it and change the value

It is basically a throttle angle measurement that tells the ECU the butterfly is in Idle position and just to inject enough fuel for idle

As you open the throttle the value increase and that sets the ECU to inject fuel for that variation of the throttle opening



Hope that Helps