Zero=Zero/250 or factory...

[mspenz]

I don't want to start another drawn out thread on the reset but I'm curious to know if anyone actually knows what the factory default is ??
I had to reset mine due to the RHS stop screw vibrating loose so I had no option, initially set it to Rogers (04RT) suggestion of 250mv and the bike ran well, also tried the Lentini method (bike still ran well) but now have just reset again to 250mv.

I've been getting occasional drops in RPM at idle or when stopping suddenly without blipping the throttle and only with a hot engine, idle drops to around 800rpm for a few seconds but it is even and never cuts out.
Checked the battery and the voltage is ok and doesn't change when the rpm drops, Hall sensor and Lambda have been swapped as have the stick coils, valve clearances and TB balance are perfect.

The LHS cable adjuster is almost fully down but the RHS still has plenty adjustment range so I'm wondering if the butterfly's or bushes in the TB are well worn, the LHS TB has a bit of a 'knocking' coming from it but RHS is quiet...spark plug on the LHS is also showing a slightly weaker mixture.

None of this may have anything to do with the idle dropping and I know that some prefer a low idle anyway but when it suddenly drops from around 1150 to 800 there has to be something not quite right

I did read somewhere that the oil temperature sensor can cause idle issues but I don't have a spare to swap out and try unfortunately.

It's been hooked up to a GS911 and there were no errors showing.

And someone must know what that factory TPS setting is .....


Mike.

 

[Comfy Old Boots]

The knee joints connected to the thigh bone, the thigh bones connected to hip bone the ...

 

[Roger 04 RT]

I don't want to start another drawn out thread on the reset but I'm curious to know if anyone actually knows what the factory default is ??
I had to reset mine due to the RHS stop screw vibrating loose so I had no option, initially set it to Rogers (04RT) suggestion of 250mv and the bike ran well, also tried the Lentini method (bike still ran well) but now have just reset again to 250mv.

I've been getting occasional drops in RPM at idle or when stopping suddenly without blipping the throttle and only with a hot engine, idle drops to around 800rpm for a few seconds but it is even and never cuts out.
Checked the battery and the voltage is ok and doesn't change when the rpm drops, Hall sensor and Lambda have been swapped as have the stick coils, valve clearances and TB balance are perfect.

The LHS cable adjuster is almost fully down but the RHS still has plenty adjustment range so I'm wondering if the butterfly's or bushes in the TB are well worn, the LHS TB has a bit of a 'knocking' coming from it but RHS is quiet...spark plug on the LHS is also showing a slightly weaker mixture.

None of this may have anything to do with the idle dropping and I know that some prefer a low idle anyway but when it suddenly drops from around 1150 to 800 there has to be something not quite right

I did read somewhere that the oil temperature sensor can cause idle issues but I don't have a spare to swap out and try unfortunately.

It's been hooked up to a GS911 and there were no errors showing.

And someone must know what that factory TPS setting is .....


Mike.

None of us know the TB factory procedure but z=250 gets you close. The factory spec on the TPS is that 250 mV equals zero degrees. The final TPS after setting, with the throttles on the stops, is 340 mV, that's for sure too.

Is yours a twin or single spark?

If you use your gs-911 to capture all realtime values like this guy did we may see an issue: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=972617#Post972617.

 

[mspenz]

Thanks for the reply Roger.
It's a twin spark (have mentioned that the coils have been swapped with a couple of spares) and done 60k miles. Unfortunately I don't personally own a gs-911 and I have to pay for the privilege but I'm not sure if the garage is fully up to more in depth usage and capturing realtime values, I'll have a chat with the mechanic first before deciding to take the bike in.

I had already read that thread and my problem is quite opposite in that the bike starts and runs perfectly cold with little or no rough running and only occasionally drops to a low idle once up to 5 bars on the RID, it is happening more often and has been doing this for around 6k miles now.

 

[mspenz]

The knee joints connected to the thigh bone, the thigh bones connected to hip bone the ...

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[Roger 04 RT]

Thanks for the reply Roger.
It's a twin spark (have mentioned that the coils have been swapped with a couple of spares) and done 60k miles. Unfortunately I don't personally own a gs-911 and I have to pay for the privilege but I'm not sure if the garage is fully up to more in depth usage and capturing realtime values, I'll have a chat with the mechanic first before deciding to take the bike in.

I had already read that thread and my problem is quite opposite in that the bike starts and runs perfectly cold with little or no rough running and only occasionally drops to a low idle once up to 5 bars on the RID, it is happening more often and has been doing this for around 6k miles now.

It could be something mechanical of course and I'll let others offer their thoughts on that. But in order to idle well, all three coils, all plug wires and all four spark plugs need to be functioning properly. If one of the lower plugs, wires or coil is breaking down, it has the effect of retarding the timing since only one plug (upper) is igniting the mixture.

I found my bike idled a lot better after I added the 2nd Load Relay, which if it's installed stock, sits to the left of the coding plug. Do you have a 2nd load relay? I added one.

 

[mspenz]

There's only one relay fitted so maybe something I will look into over the winter as I'll park it up from mid November until late March, this will give me plenty of time to have a proper look at everything as I've been using the bike so much and not had the spare time to investigate further!

Frustrating because it runs really well, idles smoothly (except when it decides to drop 300rpm for a few seconds) and returns 50mpg

Weathers looking good again this weekend so MOFF for a few days running around, plenty of boring chores to do at home but they can wait