The adjusting screw on the bottom of the transducer shifts the output point at idle, as best as I can determine.

Clockwise will reduce vacuum and firm the shifts. It doesn't have a lot of range. I've got these fully clockwise and the shift quality is acceptable, but not what I'd call "firm".

OK Guys,

Now we're cookin with gas......

Still need location of Item #80, Control Unit (referring to schematic from above).....

Still need any electrical info available on control unit.....i.e. what is the "at rest" (ignition off) condition of the outputs to any ot all of the devices that it controls......

What are the input signals, and where do they come from???

Pin or terminal diagram.....

Schematic.......now that will be a big time plus......then we couls get them tested at our local electronics/computer geek's shop......

Keep the ideas and facts coming....

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Folks,

We still need some info regarding the purpose of the "Vacuum Converter" what it is supposed to do.......and the at rest (no power on) position of it's ports.........

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

G'mornin' Folks,

Does anyone know what the Switchover valve, #81, on schematic in second post is supposed to do in regards to flow??

When Vacuum is applied to it's upper port (Vaccum Source), should there be vacuum at it's lower port (Vent)? Does anyone know a proper test proceedure for this valve???

My particular problem appears to be in this area, at present I have the Vent plugged, and all of my vacuum systems appear to be fully functional, shutoff at the key is instantaneous, need to take a long drive to test the air conditioning system, fully, but it appears much better now that I have stopped my vacuum leak......

I began this thread in order to gather information, in hoped that the "powers that be" will eventually add this thread to the DIY section......this thread, from what I know at present should be applicable to '84 and '85 California cars, and '85 Federal cars (assuming that the 300TD and 300CD have the same setup)

Thanx Folks,
SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Shorebilly - While you were apparently making real progress with your more complex vintage diesel MBZ "Engine Vacuum System" I was doing a complete "restore" of my hard drive.

IF you are correct in your last early a.m. POST then congradulations are in order.

Q - Did you ever physically locate the "Control Unit" ? This is #80 on: http://www.peterschmid.com/vacuum/1977_1985/617_95/1984_1985.jpg.

Also I would suggest for good measure that you clean the various in-line restricted orifices and the surge dampener. These appear as #63 and #85 respectively on this same diagram.

Once you have things working properly, I would put a new in-line fuel filter on the end of the vent line that is under your dash... "a" on the diagram. Such a cheap paper filter will help to reduce dust/dirt from being sucked in through this vent opening.

And as a final task I would suggest a similar in-line fuel filter [this one needs to be a clear "see-through" type] could be installed in the vacuum line that runs between the IP shut-off valve at the rear of the IP and the ignition switch... this positioned in the engine compartment in such a way that it is readily visible to you when you pop the hood. This will slow down any oil leak and serve as a visible "tell-tale" that hopefully you will catch before oil gets into the vacuum portion of the ignition switch and eventually leak down onto your shoes/pants leg. This can happen when the diaphragm in the IP shut-off valve springs a leak but has not failed completely and caught your attention because the engine will not shut off!

I'm sure there is more for you to do and report upon in this THREAD so I will be most interested in following along. Good luck with this most interesting project.

Just think, I have to deal with the CA version of this same "Engine Vacuum System" on my in-law's '85 300SD [a W126 limo] with all the automatic things to deal with.

Now back to bed for me !
Sam

Is that a vacuum solenoid?

If so, then it's simply a switch for the ARV. When switched in one direction, it connects the top port (supply) to the side port (ARV). When switched in the opposite direction, it blocks the supply and connectes the side port (ARV) to the bottom port (vent).

At no time should the vent be connected to the vacuum supply.

BTW, you can remove that entire circuit to the ARV, if you wish. It's simply an emission control device to dump turbo boost to allow the EGR to function properly. It's not worth troubleshooting.

Additionally, get rid of item #84 and plug the supply line. This device simply operates the EGR and you don't want the EGR running at any time.

Folks,

I just have been looking through my Model 123 Service Manual Library from MBUSA Classic......as I said before in this thread, the German way of record keeping may not make sense to us, but it does make sense if you think like a German......anyhow....I found the following schematic and info.....at present I copied it to Word.....I can print it and scan it later for a bigger copy.....the locations are not in the same area of the manual as the schematic was....but a great deal of info is hidden in those CD's

Check out the attachment....&%#@!%&(*^.....I have to make it smaller somehow......would someone please tell me how to post a bigger file here....maybe I can e-mail it to a moderator or somethin'

I have found the electrical schematic for the EGR system.....but not the Control Unit.....but.....EGR Control Unit is located behind right hand kick panel........

drat....can't paste to there either.......

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Shorebilly,
I too own one of the CD based official MBZ manuals [$150.00] and must admit the base program that leads you through the process of identifying and then using the underlying "PDF" files... that base program is the PITS... so I often use it just long enough to identify the "PDF" file name grouping for the subject and then just dive in and access the group of files directly browsing them file-by-file.

Do you know any of the "PDF" file names you are talking about?

Most, if not all, of these "PDF" files were made in the graphic mode and so they tend to be quite large so I don't think you are going to be able to post them on this FORUM's WebSite.

Until I can figure out how to set up some of the FREE WebPage space I have with my ISP, I have been asking people to e-mail me and I then send them the applicable file directly attached to an e-mail

It sounds as though you have made considerable progress so don't let these stumbling blocks throw you off. With the help of others on this FORUM, particularly those on the Diesel Discussion FORUM, we will try our best to continue helping. I'm hoping to have up to ~5mb of OnLine space soon I can set up as a WebPage for storing files that can be downloaded by anyone interested.

Here is the OnLine MBZ manual WebPage:
http://mb.braingears.com/ has the MBZ manuals OnLine...

I'm going to see if I can ID any PDF file groupings that pertain to any of the subject areas you are working on. I've tried in the past and didn't make much progress. If only these were not graphic PDF files... if only the text in these files was stored as text, not graphics!

Regards,
Sam

Howdy Folks,

Sorry I didn't get back here sooner.....I printed those PDF Files...then scanned them.....this is the best that I can do and still get them to a size acceptable for posting.......

First the "EGR Schematic".......#$@@%&*^#...it's still too big...

An exerpt from that schematic.....that I cropped to allow for a better view of text.....


The location of the file in my 123 Library is under
Electrical Troubleshooting
Wiring Diagrams
Index says page 108.....pdf page is 15

I had also found the location of the EGR Components, that file is still too big for posting.......by clicking "Component Location" in the bottom center of the Wiring Diagrams Index ... .pdf ..... index page 1

I will work on making these files smaller....but it's getting to the point where you can't see much when you zoom in........

You paid $150.00 for your CD Library??? Mine cost 20 Bucks on MBUSA Classics webpage.....direct from MBUSA......it sure is a ***** to use Acrobat 5.0......not searchable.......but very useful.....so far......

My vacuum problem is solved......car has barely perceptable shifts, Climate control working well, car shuts off with key, and door locks are working....I have the Vacuum Supply to "Switchover Valve for Turbo Boost Dump?....plugged....I think that this little valve must be stuck internally....leaking by.....vacuum to vent......and it really does vent my vacuum, just retains enough to allow Power Brakes to work !!!! That was before plugging the Vacuum Supply......

Thanx All......will take some photos of transmission vacuum device on Thursday AM......have access to my buddy's lift in the early AM....

SB

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Shorebilly - as a finale to your THREAD, you might try to compose a succinct summary of what has transpired with your project... what the initial symptoms were, to the steps you took along the way, to your final steps to resolve your problem. This is a good way to leave your THREAD in the WebSite's database for posterity and futurer reference. Please take the time to do this for your project has come and gone much like a whirlwind and I for one feel there is much more substance in it than meets the eye... thus far!

Thanks,
Sam

G'mornin',

I will write a nice summary of this, perhaps this weekend......

I am putting my car up on a lift later this AM, hope to take some photos of Transmission Devices......

To those guys in the "Over Boost" thread......I hope that this helps......just posted a comment over there......

I sincerely thank all who have helped me here, at present I have my "Boost Dump" and "EGR" vacuum supplies plugged off......am still deciding if I should just eliminate these devices....or the "li'l engineer on my shoulder" keeps saying...fix it, fix it, keep it stock, fix it......and the "li'l hot rodder on my other shoulder" says.....get rid of it, clean it up, make more HP, you don't need it.......

SB

__________________

Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

Hey Shorebilly,

I know this thread is a few months old and you've probably moved on to other problems issues with your '85, but I was wondering if you'd still be interested in writing a summary of the original problem and the final resolution. Did you end up bypassing the boost dump and EGR, or did you reconnect?

So far this thread has been the most helpful in unraveling the uniqueness of my '85s tranny (also a Federal). My issue is with an intermittent hard shifting (worse when the engine is cold). Now at least I think I have enough info to start troubleshooting.

Thanks for the great thread!

__________________
Obiwanrazzy
1985 300D 267k and hemorrhaging...

As I was trying to figure out the vacuum system on my '85 SD I found it has CA emissions. The new (used) engine was installed (and messed up!) by a MB dealership and apparently it has CA emissions because the vacuum diagram in this threat matches exactly what I have. What else besides the vacuum system might be different from federal emissions and what can I remove / disconnect to optimize performance? Can I just 're-convert' it to federal?

__________________
'99 S420, 155k
'91 VW Vanagon GL, 150k
'85 VW Vanagon GL, 120k
'82 VW Westy, aircooled, 165k

Firstly, Hello All.

I have what appears to be the exact model of MB as pictured in this thread.
My problems are as follows:
- Hard 1-2 shift
- No shift to 4th (stays in 3rd) and, it seems as temp rises, no shift to 2nd (no 3rd or 4th)
This can all be alleviated by disconnecting the transmission output from item#80 (flying saucer type thing) however, the car won't shut off - DUH! It Shifts great with this line disconnected.
I have a new vacuum modulator for the transmission which I assume is located on the Driver's side (correct?) but have not installed.
I have replaced the rubber vacuum lines as they were rotted.
I have not cleaned the lines (banjo fittings, hard lines, etc.)
I am mostly in the research phase of this project but would love to eliminated this issue as this is a great car pushing almost 300k miles!
I would greatly appreciate any input from the enlightened - pretty please.
Thanks again,
Adam

For anyone who's still interested, I believe #80 (Control Unit) in the diagram in the second post is what is commonly referred to as the EGR Control Unit. It's located behind the passenger side kick panel.

You can read about it and see pictures in This Thread

Cheers.