Bmw 3.0Si D-Jet Bj 1974 - fine tunning

More photos...

The intake independant tubes

The blue dot MAP (for the blue dot ECU that I don't have... Yet...)

The NEW idle speed... First time it idles correctly since 1986...

I first tunned the CO with my nose and ear. Then, my little gunsons CO machine warmed up and told me it was on 2.2%.

I really didn't have all the information about the D-Jet. You were great!
Now I have all the D-jet parts checked.

Hi Antonio,

I have seen a few European BMW MAP sensors and I have two BMW ECUs here, one even new (old stock). They do not have colour markings. You must check the Bosch numbers on them. On MAP sensor it is punched into it and must read 0 280 100 030. for European cars or 0 280 100 047 for US cars. ECU should be 0 280 001 007 for Europe or 0 280 001 013 for USA.

Congratulations to you...

Must go to bed now.

Hope to hear from you again.

Regards
Norbert

- Did you read my posting with the user manual? I think, it's really helpful, contains much more information I'm used to OEMs give to their customers.

And after a test drive... Another fine tunning issue appears...

When releasing the throtle suddenly, the engine almost stalls (sometimes it stalls) and then makes a "saw" accelaration to 1200rpm and stabilizes again on 900rpm.
On the carburetted models of this Car, a throtle damper exists to prevent this.
And on the d-jet??

Thanks once again!

My car has a 'dash-pot', too.
But it's an Opel...

Regards
Norbert

Yes Norbert, Thanks for showing the manual! Perfect.

Volker, Thanks a lot.

The part numbers are those ones for european cars. Correct.
But I have ECU with red dot and another with grey dot.
And the only good MAP is the blue dot one.

Calibration markings as far as I could find

Good morning,

Afraid of the new behavior on a cold start, I tested it today at 7 AM. Temp 10 degrees.

Turned key and fuel pump on for 1-2s as usually.
Ignition for about 5s and it started (cold start injector not working?) at about 1000rpm (instead of 1500rpm as before).
Don't consider it a bad cold start but, a little bit more revs would be perfect. Maybe 1100rpm.
What do you think?

Good morning Antonio,

well correct revoltuons on cold start depend on auxiliary air slide valve (aka air regulatr). It has an expansion element that measures soolant temperature and thus opens an air bypass a bit more or less. Increase from 900 to 1100 sounds reasonable to me, as long as your engine runs round.

Regarding colour markings: Those were known on Volkswagen and Mercedes-Benz via stickers. I remeber having seen that BMW had slight changes on their ECUs and MAP sensor over the years, but that is normally readable from the year of make (like 231: meaning 72, November). But those changes were very small and there is no rule in Bosch workshop manual that you can only combine these ECUs with specific MAP sensors. Such rules exist in other cars where you have ECUs with 2 or more different Bosch numbers and then they must be combined with MAP sensors of specific numbers as well. Is there anything official about these colour markings? Never seen them on BMW so far (or maybe I just do not remember).

Bosch workshop manual has no restrictions on combining ECUs and MAP sensors of various years of make. So they would have freely exchanged them. And they also only show one BMW part no. Did they have several or also just one? If you wannt to be on safe side, take ECU and MAP sensor with a late (75) year of make. So FD must start with a 5.

Hi Antonio,

I checked the instructions for Bosch workshkops as well and there was only a hint about the BMW specialty of doing after start enrichment via cold start valve. No hint for combining ECUs and MAP sensors of special colour as I found on Citroen DS 21. So if you had such an instruction, I would be curious to see it.

Hello Volker,

The information about the combination of the ECU and MAP according to the colour dots marked on then was something that I read when I was searching the net for some info.
And all the parts I have for my Bmw have colour dots.

Regards
Mota

Hi Antonio,

I would appreciate if ou could show me the link. I am cuious to see whether it is a Bosch technical instruction (that I do not yet have) or someone else's idea. I have checked both my ECUs and I remember both MAP sensors I had in my hands, all for European BMW. None of them has such a mark. ANd if I look at colour marks that Bosch uses from time to time, it does not look similiar either.

That is why the link to what you read might help to investigate further.

I think it was here:
e9coupe.com/forum/showthread.php?t=6250

Hi,
I recherched the Opel and the Bosch listings and found something very similar at the Opel-listings, no remark at Bosch listings (the ECU is not listed in the 'Kennliste', but in Bosch's workshop manual):
0 280 001 001 ECU Opel Admiral <first edition>
and this part # at Opel listing with the following remark: "up to stamp 904 (lean); from stamp 905 (rich)"
combinable with MAP 0 280 100 005 (normal) | B 280 001 110 <motorsport part!> or 0 280 100 014 (rich). <follows the part I don't understand at all>: Use MAP 'rich' only in combination with ECU .....001 with stamp 904'
This is not remarked at Bosch Workshop-Manual at all nor is the MAP ...014 to be found there, but it can be found in the electronic part's catalogue.

I found the information in a Technical Information issued from Opel for the service, dated about 1973 / 74.

Regards
Norbert

Add: I now found a reliable link concerning the Information about the BMW pairings:
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Well,

I am impressed what one can learn as new about D-Jetronic every day. I knew that Bosch had sometimes issued improvements in ECUs and MAP sensors, even without changing part no.s . I have seen such colour spots on Citroen ECUs in the past. I had also seen that on Bosch internal technical instructions. But I had never seen some on cars like BMW or Mercedes-Benz. So I did some phone calls and this is the result: It seems to be official in BMW and they do have by far the most changes over time, 5 versions of MAP sensor even!

What I could see was following versions of ECU / Was ich gesehen habe sind die folgenden Steuergeräte:

ECU	FD (Fertigungsdatum = year of make)
0 280 001 007	from start of series
0 280 001 007	from 129
0 280 001 007	from 132

And the MAP sensors / und die Saugrohrdruckfühler:

MAP sensor	FD (Fertigungsdatum = year of make)
0 280 100 030	from start of series
0 280 100 030	from 129
0 280 100 030	from 132
0 280 100 030	from 523
0 280 100 030	from 532

So looking at that information we have 3 correlating changes in ECU and MAP sensors: No marks would then fit to start of series, blue to 71 September, red from 71 November . But then we have additonal MAP sensor only changes in 75 September and 75 November (maybe those are the green ones?). It seems that MAP sensor was enriched in part-load curve over time and reduced in full-load therefore. In parallel speed correction function block was modified to compensate. In that logic combining a late (red?) MAP sensor with an early (unmarked?) ECU could indeed create a little rich mixture.

Well, Antonio and Norbert, thanks for hinting me to this information!

Hello,

Finally I came back from work away from home for 3 days and immediatelly went for a nice drive on my Bmw 3.0Si from 74. The first long test after the idle-run adjustment and new CO adjust.
Much more enjoyable now. The some Power and huge troque but with silent and stable idle. No more stop at traffic light with the big six reving loud to the astonished (and a little bit affraid) other drivers.

Regards from Portugal
Mota

Went to my garage to check once again my ECU's and MAP.

The original ECU has a red mark. The reserve one has a silver mark. Both 0 280 001 007.

The MAP on the Car (replaced by myself several years ago) is a VW MAP after all... Brrr... 0 280 100 008... With blue mark...
But the Car runs astonishingly well with it.

O must find a Bmw red mark MAP.

Regards
António

Hi Antonio,

well that is odd. According to Bosch a 0 280 100 008 MAP sensor does not exist (in the field?).

Hallo,

Today I used the Bmw 3.0Si as family car.
Did about 100km . Very smooth km.
Fantastic!

With the AC working very well all the time. More than 30ºC outside.

With the 900rpm idle-run, and AC on, sometimes it stalls if I leave the throtle suddenly. The carburetted version has a throtle damper, why not on the D-jet?


Some photos