1150 Throttle Buterflies and TPS Setting

[Paul Dilley]

This was inspired by discussion between Motorman and Cookie.
and referred to setting up TPS and butterfly opening after losing original factory settings.
My thoughts and question-
Manual for GS says butterflies should be at 15 degrees from shut. If this is the same setting as the bench flow setting at BMW what is the Voltage reading at the TPS. The zero zero settings mentioned in other articles seems to be on RS models which have a 10 Degree opening. Therefore zero to 10 degress gives X reading on a voltmeter whereas 15 degress would be zero X plus another 5 Degrees maybe.
What about the brass bypass screws - how many turns out should they be?
Help please

 

[DrAlf]

No feckin idea – can you find out and then do mine for me please

 

[Guzzler]

1. On the R1150, DON'T mess with the throttle stop screws. Unless you ABSOLUTELY know someone has messed with them. The "zero-to-zero" method really doesn't translate well to the 1150. Trying to adjust the stop screws to get the butterfly's back to 15 degrees is a royal pain for the average home mechanic. Actually it's a pain for a dealer mechanic, the majority won't even attempt it. They just order new throttle bodies.

2. The TPS voltage should read between 0.32 - 0.40 V. The preferred voltage is 0.36 V from reading from Pin 1 and Pin 4.

2. To set the brass by-pass screws... I prefer to seat the screws (just seat them, don't twist them down hard), hook up your prefered manometer (twinmax, carbtune, mercury sticks, etc). Start the engine (yes it will start with screws seated), balance the TB's. Then back out the screws equally till you get the desired idle RPM of 1100 ± 50 RPM (remember to keep the TB's balanced in the process). Remember what they are... "Idle Air By-pass screws".