Idle question

[petkostas]

Quick question, bike runs fine apart from a small issue with my idle, I have set the idle to around 1100 RPM, after a while the idle drops to around 900RPM unless I blip the throttle, sounds normal? Generally when it's idling at 1100RPM feels just fine but after a while (like waiting at the traffic light) it feels dropping a bit and like it's ready to stall (hasn't happened, apart from sometimes when the temperature RID is empty and I blip the throttle).
1150 2002 model (non servo).

 

[Rabbitson]

Sounds to me like the throttles are not correctly balanced.

If you are a little confident and have a twinmax you can do this yourself in about half an hour, otherwise it doesn't cost much at the dealer.

HTH,

David

 

[petkostas]

Sounds to me like the throttles are not correctly balanced.

If you are a little confident and have a twinmax you can do this yourself in about half an hour, otherwise it doesn't cost much at the dealer.

HTH,

David

Throttles are balanced and the idle set as well using a carbtune...
Apart from the idle the bike feels way better than before in all RPM range (used to be a bit rough on the higher end, feels like a charm now), the rough idling was present on my previous services as well and that remains my only mystery for the moment

 

[davegs]

Idle

What are the rubber caps like underneath the throttle bodys? if perished this may be the prob.

 

[petkostas]

What are the rubber caps like underneath the throttle bodys? if perished this may be the prob.

Nope they are fine, I had them checked good condition and tightly set on them, I was thinking of making an air leak test, if I had an air leak wouldn't that be apparent in the whole RPM range?

 

[mazi]

I have the same in my R1150GS '02. Do not know why. When cold it is ok, but when it gets warm, the idle can drop but not always.

Had a similiar thing in my former R1150GSA '05, but there the idle increased a bit.

No air leaks, throttle bodies set up correctly in both bikes.

I read on advrider.com that damaged ECU can cause that - a guy swapped his ECU and the bike started to run perfectly on the idle.

 

[petkostas]

I have the same in my R1150GS '02. Do not know why. When cold it is ok, but when it gets warm, the idle can drop but not always.

Had a similiar thing in my former R1150GSA '05, but there the idle increased a bit.

No air leaks, throttle bodies set up correctly in both bikes.

I read on advrider.com that damaged ECU can cause that - a guy swapped his ECU and the bike started to run perfectly on the idle.

Sounds to extragerated to be an ECU, if I had other kind of problems I would be suspecting the ECU, but since the bike runs wonderfully in the whole RPM range, I can't think that this could be a faulty ECU.

 

[mazi]

My bike runs perfectly too and on the idle it does the same as yours.
That guy's bike also ran ok, but on idle it started to do as above. He checked everything including the ECU and it caused the problems.

Regards,
Mateusz

 

[petkostas]

My bike runs perfectly too and on the idle it does the same as yours.
That guy's bike also ran ok, but on idle it started to do as above. He checked everything including the ECU and it caused the problems.

Regards,
Mateusz

Gonna have it at the back of my mind, but since I can't check the ECU, I will be moving initially with the air leak test and then maybe some TB checks to see if I can find anything.
I am also suspecting the lambda sensor, going to try and see if I can remove it on the fly and do a small test.
Also a small update, noticed today, when I fire up the bike the idle seems quite steady, it changes once you touch the throttle (either blip or start rolling), ain't that dramatic, but it feels as the engine either ain't breathing that good or the mixture ain't that good, all that while idleing always, no probs when you either blip the throttle or on the move.
Spark plugs have been changed to NGK iridium from motorworks, TB's where balanced just a few km's away (the problem was there even before the TB synch), air filter and fuel filter where changed like 12000 Km's before...
Also I noticed the following today, while decelerating I can hear a rattling sound from the left cylinder, suppose I am heading for a cam chain tensioner?

 

[MattW]

Have you checked the TPS?

See if the voltage always returns to the same value after operating the throttle.

 

[petkostas]

Have you checked the TPS?

See if the voltage always returns to the same value after operating the throttle.

Going to check it probably today let's see what we get from there...

 

[petkostas]

For the sound I am apparently heading for a new cam chain tensioner, ordered one from motorworks and waiting for it (only if that happened 1 week earlier when I had another order placed).
For the idle I am prolly going to check if I get the time this evening for possible air leaks.

 

[MattW]

For the sound I am apparently heading for a new cam chain tensioner, ordered one from motorworks and waiting for it (only if that happened 1 week earlier when I had another order placed).
For the idle I am prolly going to check if I get the time this evening for possible air leaks.

Did you check the tps voltage (and whether it returns to the same value)?

 

[petkostas]

Did you check the tps voltage (and whether it returns to the same value)?

Not yet gonna do it prolly later
Thanks for the tips mate I will let you know my findings.

P.S About the cam tensioner, I can hear the rattle which get annoying especially in deceleration, from like 3000RPM coming to a stop on the lower gears and also while on neutral and revving the rattle follows the throttle responses, it's not the TB's (checked them) and from what I heard (various videos on youtube) it should be the chain tensioner (believe so, haven't ever had the chance to encounter such a noise on my previous bikes), does it sound something like that to you?

 

[MattW]

Not yet gonna do it prolly later
Thanks for the tips mate I will let you know my findings.

P.S About the cam tensioner, I can hear the rattle which get annoying especially in deceleration, from like 3000RPM coming to a stop on the lower gears and also while on neutral and revving the rattle follows the throttle responses, it's not the TB's (checked them) and from what I heard (various videos on youtube) it should be the chain tensioner (believe so, haven't ever had the chance to encounter such a noise on my previous bikes), does it sound something like that to you?

I fitted the updated cam chain tensioner to my 1100. For me it rattled like a sack of nuts and bolts on startup but was quiet afterwards. The new tensioner fixed this.

That's not to say that your rattles aren't the tensioner - I've heard other 11xx's which rattled at various other times and it certainly can't hurt to fit it

When you unbolt the old tensioner, it'll leave the spring and tensioner piston in the hole - make a wire hook to get the spring and then open out the hook so you have to force it into the piston - it'll grip it and allow you to withdraw it.

The new tensioner is a one piece item so it just drops in.

 

[petkostas]

I fitted the updated cam chain tensioner to my 1100. For me it rattled like a sack of nuts and bolts on startup but was quiet afterwards. The new tensioner fixed this.

That's not to say that your rattles aren't the tensioner - I've heard other 11xx's which rattled at various other times and it certainly can't hurt to fit it

When you unbolt the old tensioner, it'll leave the spring and tensioner piston in the hole - make a wire hook to get the spring and then open out the hook so you have to force it into the piston - it'll grip it and allow you to withdraw it.

The new tensioner is a one piece item so it just drops in.

Thanks mate!
Saw the replacement pictorial over advrider believe it's going to be an easy job!

 

[petkostas]

Solved

Case solved!
Once again thanks to ukgser, well it was not posted in this thread, but the on going debate regarding the CCP gave me a hint...
Got back today from work, bike was riding as usual, strange idle behaviour (after a couple of seconds) pulling ok across the range, but sometimes feeling a bit reach...
well that reach sensation got me into looking in various aspects, got to the CCP mode thread, so what the hell, let's take a look...
Remove seat, open fuse box, and hey presto...I got the CCP in there, but the yellow jumper thingy...is pulled off and placed as a spare...I could still remember that view the first day I checked the fuse box (but had no idea what that yellow square thing was for), so what did I have to loose? nada, placed the plug back, and magic happens...bike is working wonderfully, pulling as it was in all RPM range and it feels running as it should around the idle and bellow 2000 RPM when pulling away from the stop light (had a feeling of running reach before).
Thanks everyone!

P.S Bike was serviced twice from 2 different official BMW shops (before I laid my hands on it) noone ever mentioned to me...hey you are running a stock bike why is you plug...unplugged in the fuse box...

 

[MattW]

Excellent

 

[petkostas]

Noise has been also successfully resolved, it was indeed the cam chain tensioner, got it yesterday from motorworks and installed it
So if you have the following symptom I guess it should fall under the cam chain tensioner replacement:
1) Noise when bike gets warmer from the LH cylinder.
2) Strong rattling / tapping noise when decelerating to come to a stop, when the RPM drops, I used to have a strong annoying rattle which transformed to a knock when stopped.