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#760124 - 02/16/12 03:48 PM Re-calibration of TB to factory spec?
NJNeal Offline
Member

Registered: 09/30/11
Posts: 116
Loc: Northern NJ
In my ongoing attempts to deal with surging, I took the bike in to a local BMW dealer to restore TPS to factory settings and to re-sync TBs. This is not the dealer from whom I bought the bike 6 months ago.

Bike is 2003, 1150RT, single spark, with Techlusion 1032ST installed.

New dealer called me today to tell me that the screws with the blue paint dots have been disturbed, that the TBs cannot be synced as a consequence, that one BBAS is at almost full out and the other almost all the way in, and that their fix is to replace the TBs with new ones.

I called the dealership where I bought the bike, where it was bought new and serviced its whole life. They claim that none of their techs would touch those blue painted screws.

Question: Is there any way to get back to factory settings on the TBs? Is my only solution new TBs? Needless to say this was frustrating news.

Thanks for any opinions.

Neal
_________________________
1978 R80/7
2003 R1150RT
I'd rather ride than wrench.

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#760127 - 02/16/12 04:02 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
Peter Parts Offline
Member

Registered: 09/01/09
Posts: 1824
Loc: Toronto and Delray Beach, FL
Your final question is a very good one which I've been thinking about for quite a while. Maybe we'll get some answers now.


(Some folks will answer, "yes, zero=zero" and in Mr. Rogers neighborhood, everybody's opinion is wonderful......)

The problem is that The Factory sets those blue-paint-sealed screws at a certain volume of air flow for a given vacuum. But nobody knows what that volume is.

You can get the two TBs about the same and maybe in the ballpark for flow (using flow measurement at idle). And maybe that's all you need to fuss about.

Ben
_________________________
R1100S, 1999 (don't know much about other models)
Riding 52 years but only last 47 on BMW boxers
Bike writings: http://www.tinyurl.com/6bvt23
(includes a 6400 mile trip, 20 days, with wife to LA)

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#760132 - 02/16/12 04:27 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8364
Loc: Ohio
Afternoon Neal

To get them back to FACTORY specs they need to be sent back to Bing. (big bucks if they will still even do them for you)

But they don't really need to be back to factory specs to work correctly.

It takes some work & cross checking but it can be done at home or by a competent & BMW knowledgeable technician.

It sounds like your dealer is not able or willing to take the time to get it back to close to proper operation so you probably have a few choices.


* Do it yourself but it will take persistence & the willingness to adjust your balance & cross side balance & TPS multiple times while chasing it back close to factory specs.

*Do as the dealer suggests & put BIG money into new TB units (not a prudent choice & probably won't solve your surging

*Or find another dealer or independent mechanic with both the willingness (AND KNOWLEDGE/ABILITY) to get those TB's back where they belong.

OK, now my take on your problem-- If you have the TPS set correctly & can get a cross side base-idle balance & above-idle sync then your surge problem isn't going to be solved with new TBs with properly set curb idle screws.



Added: the thing I can't understand is people thinking that those base idle stop screws are mystical & can't be moved without turning the TB's into junk. The factory base air flow setting is only valid on brand new TB's with no shaft wear & no bore coking. Once the shafts wear a bit or the bore (or throttle plates) coke a bit then those factory settings are not at base factory air flow anymore.


Edited by dirtrider (02/16/12 04:49 PM)
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#760144 - 02/16/12 05:33 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
NJNeal Offline
Member

Registered: 09/30/11
Posts: 116
Loc: Northern NJ
D.R.
Thanks. Has anyone written a procedure for getting to a reasonable base setting? Neither dealer is willing to address this.
N
_________________________
1978 R80/7
2003 R1150RT
I'd rather ride than wrench.

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#760149 - 02/16/12 05:48 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8364
Loc: Ohio
Evening Neal

Not that I know of on the 1150 system. On the 1100 the 0=0 will get it close to start with but it still has to be wiggled in to get the BBS set to specs & the hot curb idle RPM correct with the TPS @.385v.

The 1150 has different TB's & uses a learnable TPS system.

If your idle RPM is close now & your TPS is set to around .365v you can wiggle it in from there. To do it right though you really should remove both TB's & clean all the carbon out inside the bores as well as the BBS air passages then re-bush and or replace the throttle shafts if they are loose. A few thousandths of an inch deflection can really effect throttle plate centering & air flow at closed throttle.

If you have a lot of internal coking or loose throttle shafts it won't be correct until you get those areas corrected first. You can still do the base settings but the results will be much better with proper centering throttle plates & no coking.
_________________________
D.R. ___
Sent from my rotory dial wall phone!

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#760150 - 02/16/12 05:48 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
nrp Offline
Member

Registered: 12/22/04
Posts: 647
Loc: Minnetonka MN
I've written & posted it several times for my R1100RT. I used the engine itself to set the throttle stop opening.

You will have to clean the throttle bodies and BigBrassScrews and then carefully set the intake valve clearance first though.

Let me look for my posting. back soon.

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#760152 - 02/16/12 06:03 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
NJNeal Offline
Member

Registered: 09/30/11
Posts: 116
Loc: Northern NJ
Would it be reasonable to:

(1) set TPS to .385v
(2) adjust intake valve clearance
(3) clean BBAS passages
(4) set BBAS to 1.5 turns out from clos
_________________________
1978 R80/7
2003 R1150RT
I'd rather ride than wrench.

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#760155 - 02/16/12 06:13 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8364
Loc: Ohio
Evening Neal

Other than setting the TPS closer to .365v that would be a good start just to see where you are. (make sure the choke if OFF & you do a new TPS re-learn )

Then check the cross side idle balance & part throttle balance.

If close at idle then little tweak of a BBS screw (or above idle use cable length). If off a lot then leave the BBS set to 1.5 turns & use the idle stop screws to work it in.

Remember to keep on the TPS adjustment & TPS re-learn if you mess with the L/H TB base idle screw.

REMEMBER----Be sure to do a TPS check & NEW TPS re-learn after any change or movement of the L/H base idle screw.

If you have a lot of coking inside the TB's or worn throttle shafts/bushings you will still be off due to the air flow differences due to those.



Edited by dirtrider (02/16/12 06:15 PM)
_________________________
D.R. ___
Sent from my rotory dial wall phone!

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#760163 - 02/16/12 08:02 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
nrp Offline
Member

Registered: 12/22/04
Posts: 647
Loc: Minnetonka MN
Yr close - go to this thread (and there are others too) :
http://www.bmwmoa.org/forum/showthread.php?t=48397

YMMV since you are a later bike than mine. But you have to set the intake valve clearances and thoroughly clean the throttle bodies first.

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#760166 - 02/16/12 08:20 PM Re: Re-calibration of TB to factory spec? [Re: NJNeal]
NJNeal Offline
Member

Registered: 09/30/11
Posts: 116
Loc: Northern NJ
thanks nrp and D.R.
Question: On the left hand side cable adjustment on the TB, that adjuster is at its limit...no further adjustment is possible, last time I did a TB sync. Does this point to a need to adjust the cable at the other end, at the bowden box?
Thanks again for the guidance.
Neal
_________________________
1978 R80/7
2003 R1150RT
I'd rather ride than wrench.

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