tii throttle body lever differences: parts book help

[jgerock]

While searching for some older pictures, I remember there were some slight differences in the coupling (item # 21) that secures the throttle body shaft to the lower vertical linkage.

The shape and length of the lever arm for the accelerator return spring are different.

 

In these two pictures, the lever on the left is one I removed from 72 tii engine 2762332.  The one on the right from my 73 tii 2764081.

 

According to RealOEM, only one lever was used for the entire run:  PN 13541257036

That part number was used for the following vehicles:

1502-2002tii:  4/71 thru 11/75

1500-2000CS: 1/70 thru 8/71

5 Series E12:  3/72 thru 7/79

 

But when I looked at my old orange BMW parts book (Band 1) for section 13/34, there are (2) different levers listed:

 

13541256469

13541257036

 

Plugging the other number into RealOEM didn't produce any results (where used).

 

The parts book has the following notes:

 

13 54 1 256 469  -->  Fg    (up to chassis #)

13 54 1 257 036  Fg -->    (from chassis #)

 

2002 Tii (o)  2710776        (o = left hand drive)

2002 Tii (oo) 2750863       (oo = right hand drive)

2000 To Tii   3423208        (could this be a Touring?)

2002 Tii USA  2761944-

                       2762014

                       2762372

 

1) How can I interpret this information on the USA models from the Parts book?

2) What is the 3rd model listed above?   edit: a Touring?

 

EDIT:  Looking at Graphic 13/31 (the KF pump) shows the same chassis number changes for the vertical tii linkage(intermediate shaft) # 13 51 1 254 602 and 13 51 1 257 035

 

So the vertical linkage (intermediate shaft) and coupling were changed at the same time and should be used together.

 

 

 

 

 

 

Edited August 6, 2018 by jgerock

[wegweiser]

Remind me to get back to this, Jim. I'm still on my first cup of coffee… but when I worked for Maximillian, we had this sorted out at one point. I believe a few items changed during these production runs - some by plastic/metal runner changeover (and perhaps 121ti/E12 head) and some by pure VIN. I remember closely examining mine and when I sent off a bunch of (occasionally duplicate) items to be plated, making SURE I re-installed the original one, from my car (2762085) while I was NOT restoring it.  I'll try to check in after work, today. FYI: the long pivot rod (shown just above the oil filler cap in this photo) also changed, I believe. 

Edited August 6, 2018 by wegweiser

[jgerock]

Thanks Paul.  

 

Also I do know there are early and late throttle bodies on the tii.  The tuna cam and lever are completely different for the CO adjustment.

 

The orange parts book only shows (1) housing # 13 54 1 256 155 for all standard tii's and another one # 13 54 1 259 686 for the turbo.

 

Why doesn't it show the other housing?

Which version is the 6155 housing (early? or late?)

 

Jim 

[jgerock]

Both engines (my numbers) had aluminum runners and the same throttle body style.

I was thinking the lever was changed when the plastic runners switched to aluminum - but?

73

72

[wegweiser]

OK… here's what I see:

 

13 54 1 256 469 was used from 2760001 to 2761944

13 54 1 257 036 was used from 2761945 to 2762014

13 54 1 256 469 was used AGAIN from 2762015 to 2762372

13 54 1 257 036 was used from 2762373 until end of production run.

 

Books show the vertical pivot rods changed as follows - and may be a misprint / omission with regard to their matching the above wacky back-and-forth application:

 

13 51 1 254 602 from 2760001 to 2762372

13 51 1 257 035 from 2762373 to end of production run

 

Based on the re-issued white books, the return springs and bracket for the spring - affixed to the pump change as follows:

 

13 51 1 257 560 spring from US 74 onward

13 51 1 256 806 bracket used to 74 US

13 51 1 259 767 bracket used up to 74 US

 

I don't have the band I volume of the old orange books to tell me the early spring  number, unfortunately.

 

Other things of note: The mounting plate of the "H" shaped bell crank mounted to the block changed at VIN 2761817, as did some of the fasteners. Sadly I have no examples to photograph to tell you exactly what the physical difference is, to these parts.

 

If you look at these VIN ranges, you'll ALSO see a change from plastic to metal intake runners *AND* a change from 121 head o E12 head - as if the factory had a shortage of the "updated" intakes/heads, and had to revert to the older stuff for a few cars. (the 2761945-2762014 run)

 

There… confusing enough for you?

[Einspritz]

I am not near my orange books, but have this to offer; in 7/74 my bracket has two bolts not one, so maybe that is the discrepancy. Also, see the attached for a modification of the bellcrank shaft.

 

Also, my recollection  between the early and late throttle body is that the cam is the same but the lever system is different due to the sensitivity in adjustment. And too, at least in Europe, the injection pump fuel curves were different than the U.S. models which may correspond to your findings.

img376.pdf

['76mintgrün'02]

8 minutes ago, Einspritz said:

my recollection  between the early and late throttle body is that the cam is the same but the lever system is different due to the sensitivity in adjustment.

Isn't the difference in the screw thread pitch?  One coarse (early) and the other fine (late)?

[jgerock]

8 minutes ago, Einspritz said:

I am not near my orange books, but have this to offer; in 7/74 my bracket has two bolts not one, so maybe that is the discrepancy. Also, see the attached for a modification of the bellcrank shaft.

 

Also, my recollection  between the early and late throttle body is that the cam is the same but the lever system is different due to the sensitivity in adjustment. And too, at least in Europe, the injection pump fuel curves were different than the U.S. models which may correspond to your findings.

img376.pdf

Interesting TSB details.  I've never seen a 2-bolt coupling, but have heard of them being used on tii's (From Bill Williams).

The blue fuel injection handbook shows a picture of both throttle bodies but I've not seen their part numbers and applications.

 

[jgerock]

1 minute ago, '76mintgrün'02 said:

Isn't the difference in the screw thread pitch?  One coarse (early) and the other fine (late)?

The "lever" for the CO adjustment is different.

 

[Einspritz]

Isn't the difference in the screw thread pitch?  One coarse (early) and the other fine (late)?

 

No. It is the length of the lever arm which makes adjustments less sensitive.

[jgerock]

[Conserv]

My entirely un-documented belief is:

 

1. The throttle body change is unrelated to the aluminum runner/E12 head changeover, 

 

2. The improved throttle body (less sensitive adjustment) became the only available replacement throttle body at some point, perhaps soon after tii production ceased. Thus, one can occasionally find the newer, improved throttle body on early tii’s.

 

An earlier tii thread — with far too few owners willing to “show their throttle bodies” — was inconclusive, although there were suggestions, based on the evidence, that the throttle body change could even have been 1974-ish event.

 

For no particular reason, beyond my own nerdiness, I’m eager for some brave soul(s) to document all of these tii changes, based — to the extent possible — on VIN’s and manufacturing dates.

 

Jim and Paul, did I see your hands up, or were you just scratching your heads? ?

 

Regards,

 

Steve

 

Edited August 6, 2018 by Conserv

[Einspritz]

7/74 Turbo

 

Here you go, but perhaps not relevant as it is for a Turbo and the port is not the same, though the castings are made for both on the later units.

 

I have a NOS "replacement" which is the later style with two casting ports, but the fitment is for the Tii.

 

I have 2 '72s which are the "earlier" style, (Plastic Tubes) which I prefer. I don't have the VINs at this time.

 

Do I need to photo the whole box of "spare" throttle bodies for the record?

[PaulTWinterton]

You've got me thinking.  I have 3 complete sets.  One original set on my car #2762958 (mfg 11/72), and two sets from 74tiis.  I, too, will check for differences in intermediate shafts.

Edited August 6, 2018 by PaulTWinterton

[Conserv]

1 hour ago, Einspritz said:

7/74 Turbo

 

Here you go, but perhaps not relevant as it is for a Turbo and the port is not the same, though the castings are made for both on the later units.

 

I have a NOS "replacement" which is the later style with two casting ports, but the fitment is for the Tii.

 

I have 2 '72s which are the "earlier" style, (Plastic Tubes) which I prefer. I don't have the VINs at this time.

 

Do I need to photo the whole box of "spare" throttle bodies for the record?

 

Thanks.

 

Don’t get me wrong, I enjoy a box of throttle bodies as much as the next guy...?

 

But it seems that, theoretically, we need a lot of data points consisting of throttle bodies currently installed, along with the VIN of the engine on which they’re currently installed. Then perhaps we can determine the changeover VIN and date, provided we can also rationalize that any “outliers” from this proposed changeover must have been swapped at some point in the last 40+ years.

 

Simple! ?

 

Best regards,

 

Steve