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Rough GS Idle ?
- Thread starter wcycle
- Start date
deilenberger
A bozo on the bus
This is rather worrysome - what throttle stop screws are loose? There are two screws that are never supposed to be touched - set at the factory. Other than the cables, there is nothing "user adjustable" on the throttle bodies.
Perhaps you could point out what screw you're referring to by looking in the DIY/tech section and referring to one of the postings in the Throttle Body Sync thread there that shows the screws..
Perhaps you could point out what screw you're referring to by looking in the DIY/tech section and referring to one of the postings in the Throttle Body Sync thread there that shows the screws..
Rough Idle
Yes, these are the screws that were loose, I could tell they were tampered with before I got the bike, I adjusted the valves, and started to hook up my vacuum-mate when I noticed the lock nuts were up the whole way against the tp screw head. I set the screws so that they just touch the cable wheels, the idle got a little better, but still is rough. Now what? Thanks for the reply.
Yes, these are the screws that were loose, I could tell they were tampered with before I got the bike, I adjusted the valves, and started to hook up my vacuum-mate when I noticed the lock nuts were up the whole way against the tp screw head. I set the screws so that they just touch the cable wheels, the idle got a little better, but still is rough. Now what? Thanks for the reply.
N
New2rt
Guest
I don't know if this will work and at best it is a guess (it does hold weight on the automotive side)
You can try taking a reading of the stepper positions on another bike that hasn't had the srews fiddled with. Try adjusting the stepper position on your bike to match these using the stop screws. (using the GS 911, you can also calibrate the steppers using this tool) If it works like I THINK it MIGHT there should be a direct relationship between the stepper reading and the throttle plate position. Plate increase - stepper decrease and vise versa.
If the srews were off enough the stepper can possibly be damaged, the GS911 would let you check this.
You can try screw contact +1/8 turn for a starting point.
If this doesn't help the TB's can be sent to BMW for calibration.
I have never tried this on this system so you are on your own here but it might be worth a shot.
You can try taking a reading of the stepper positions on another bike that hasn't had the srews fiddled with. Try adjusting the stepper position on your bike to match these using the stop screws. (using the GS 911, you can also calibrate the steppers using this tool) If it works like I THINK it MIGHT there should be a direct relationship between the stepper reading and the throttle plate position. Plate increase - stepper decrease and vise versa.
If the srews were off enough the stepper can possibly be damaged, the GS911 would let you check this.
You can try screw contact +1/8 turn for a starting point.
If this doesn't help the TB's can be sent to BMW for calibration.
I have never tried this on this system so you are on your own here but it might be worth a shot.
N
New2rt
Guest
Still thinking out loud, find a friend who is willing to remove his TB and use a vacuum source (shop vac with adjustable restricter) and flow gauge (the kind used for balancing side and down draft carbs) adjust the vacuum and flow to a mid reading and without touching either one swap in your TB's and adjust the screw to match. Don't change the setting on the donner TB
Maybe, just Maybe or I'm completely out of my mind.
If you attempt to try this sillyness the air bleed ports will need to be blocked.
Maybe, just Maybe or I'm completely out of my mind.
If you attempt to try this sillyness the air bleed ports will need to be blocked.
N
New2rt
Guest
I don't have a gs911 tool. Where do I get one? I am going to try the 1/8 turn idea you gave me, I will post how it worked. I am headed to the national, might be able to find one there? Thanks.
copy and paste this:
http://www.hexcode.co.za/
Or as I just found out, click it.
Got the Mighty GS to Idle, It's not perfect, but it starts, and idles. I set those throttle stop screws just a 1/16 from where they made contact on the throttle plate, Since this system uses a air stepper, I figured the throttle plates should be almost completely closed, the stepper will send in air to make it idle. It still seems to be a little rich at idle, so I think the steppers need to be reset. It idles perfect when cold. Thanks for all of the concern and help. Rally bound. 
