Hello dirtrider,Do you know what actually is the difference in idle control between hexhead and camhead? It seems to me that the same procedure can work on the camhead also.
--No, I don't know ALL the differences, they are definitely close but I haven't ever compared them item for item.You did not mention anything about the TPS in this process. Did you have to relearn it at some point?
-- I didn't have to mess with the TPS on either hexhead that I did as neither one was messed with. As long as the TPS voltage is under the idle threshold voltage & not allowing dropped throttle fuel cut-off it shouldn't effect the idle balance or stepper position as the fueling system should be idling in closed loop (fueling based on o2 sensors not BMS-K mapping)Do you know the value of this idle threshold? Is it something that can be checked with GS-911?
How do you actually verify fully closed throttle plate?
-- I removed them & held up to a strong light then looked through while verifying the throttle plate was closed (I mainly did this to make darn sure than the throttle plates were centered & closing evenly.Basics. I really hoped you have some trick to spare me the time of doing that "RPM up to just above the stepper link up" By this you meant the point when the idle control is no longer in play?
-- At a certain point the steppers should quit being idle steppers then link to the same counts & follow the throttle open for a ways (I t-h-i-n-k) at this point they are being used a dash pot like device to prevent a quick dropped throttle engine stall. Spot on for the dampening functionality. I can even see that in action. Just blip the throttle to 4.000-5.000 RPM and after release it is clearly perceptible that the RPM will hold for a brief moment around 1.800 RPM
How can you check whether initial TB throttle cam lift starts at same time? I can recognize when they reach back to the stop screws at same time, but lift at the same time? By verifying with the TB sync tool?
--I do it 2 ways, one is to hold a hand on each TB cable cam then have someone move the twist grip. I have also watched my manometer fluid column as it is very sensitive & will show even a slight TB side lead as I slightly open the twist grip. (basically used as a verification check, if the TB cams don't start their lift at the EXACT same time then there is something drastically wrong with TB balance or engine vacuum ability) Sorry if I bother you with so much questions, but I'm pleased to finally discuss with someone who have been working on this challenging task and have something meaningful to say
--It is a very challenging task as there is no BMW defined way of re-setting those base idle screws (BMW says to replace the TB's). A flow bench would be the best way but even then we would need to know the flow rate @ what pressure drop.
Another thing to keep in mind is: There is a system voltage monitor circuit inside the fueling computer that bumps the idle RPM up (adds stepper counts) if the voltage drops to a certain point (what that point is I don't know) so make sure the battery is good & fully charged before attempting to set/balance the steppers.
Another thing that I use is large "O" ring that fits tight on the handlebar end weight, I can roll that into the gap between the end of the twist grip & the bar end weight to allow the twist grip to stay in any position that I set it (basically a poor mans throttle lock)