Very good.

So, we know that we can get the desired results with a vacuum adjustment.

Now, I'm not personally familiar with the 616, but we need to determine if the VCV on the IP is adjustable.

Please look at the VCV and tell me if it has a small domed cover on the forward end (closest to the radiator). The domed cover will be facing the left side of the vehicle (facing you when you're looking in there).

Nothing needs to be done with the modulator and nothing needs to be done with the 3/2 valves............just get that out of your mind completely and don't touch anything else.

Dude, you're probably the most helpful person on here. I very much appreciate the work you're doing for us with transmission problems.

Will post the results of a 616 VCV inspection in daylight.

__________________
1983 Mercedes-Benz 240D
Automatic, A/C, Power Sunroof, Power Right Side Mirror
231K Miles FOR SALE MAKE OFFER

Anytime. Just continue to follow suggestions on the thread and we'll sort it out. Many folks give up in the middle due to other more critical items........or just the lack of time.

I believe it does, see attached.

In the first picture, it's the pointy domed thing on the front of the VCV, near the black T connector? Its on the left side of the device, closest to the radiator.

Attached Thumbnails

   

__________________
1983 Mercedes-Benz 240D
Automatic, A/C, Power Sunroof, Power Right Side Mirror
231K Miles FOR SALE MAKE OFFER

The dome is in the second photo.........just "above" and to the "left" of the vacuum line.

See if you can carefully remove this dome..........you'll need an exacto knife to pry it off the housing. After you do this, take a good photo of what's below the dome and post it.

Hi all have now read this thread from the beggining makes very interesting reading, here is my situation, I have got an 82 300TD w123 in my care at the moment, I have been entrusted to convert it from a four speed manual to an auto, I fixed up the tranny which was a donor from an 81 sedan (we call them saloons on this side of the pond) put in new fluid, gasket and filter. I took the VCV from the 81 donor car (metal type) and put a new 3:2 valve on the cam cover, this car being european does not have an EGR setup is non turbo and does not have AC or climate control so a fairly simple setup, I have no vacuum leaks whatsoever in the rest of the vac circuit central locking, shut off etc is all on new hose and all the t-pieces and joining sections are also new, The line to the modulator holds vaccum when pumped from my hand-held vaccum pump, I bought all the orafices suggested here and have tried placing them randomly in different spots round the circuit but they do not make any difference I still get 25 HG at idle every where dropping to 15HG under load, The tranny is of the older type with the smaller sump-pan and the lockout/reverse light wiring aranged vertically, the closest diagram on here to my setup is this one http://home.comcast.net/~phantoms/vacuum/engine.jpg but not exactly the same as the euro spec is obviously different. My shifts are all very late although when the engine is warm and I adjust the throttle linkage I can get them acceptable although still late, as soon as I start again from cold I am back to square one. I note that the reading is supposed to start out at 10HG and drop to 0 at full throttle, the only way I managed to achieve this is to wind the throttle linkage in so that the 3:2 valve is partially depressed I am not sure that this is right, so here is my question, On the diagrams for automatic transmission the brake booster hose has two outlets, Is this type of hose designed for automatic transmission specifically? my brake booster hose only has one outlet and measures 25HG on the vaccum pump, Does the secondary one upstream reduce the vacuum output at the hose? Could this be my problem? Hope you knowledgeable folks over there can help me because talking to a parts guy in an MB dealership here is about as useful as an ashtray on a motorbike many thanks in advance

Felix

NOOOOOOOO!!!!!!!!!!!!! Most want to go the other way.

__________________
Chad
2013 Jeep Unlimited Rubicon
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL

yup Im with you on that on Chad personally I would go manual every time still the customer is always right as they say

Felix... hello from someone who the geneologist say is a Scottsman ["Ross"] but from my Mother's side my middle name is "Millsaps" which is pure English! So hello relative!... now to your situation and questions.

I started this THREAD/subject because I felt, and still do, that the restricted orifices are NOT understood... and eventually I came to believe that they are an easy 1st step for MBz to put the vacuum shifting control system in rough balance... to get the pressure being delivered to the vacuum line that branches to both VCV and Modulator... to get the vacuum at this point to approximately the right value. We can debate what that value is but I think ~10" is probably as good a # as any. I think this number is a variable depending upon what generation of both VCV and modulator you have.

So in your case having only one vacuum "T" branching off the pump-to-booster chamber line, I think I would first probe the inside of your "T" and see just how large the internal opening is... and IF it is less than 1.5mm, then I would consider widening this while being careful to NOT degrade the strength of the "T". This will give you the greater vacuum capacity I think you will need through the single "T"... capacity for both shifting control as well as the door-lock system(s). Without aa ACC system with 5 leaky vacuum elements, you can probably get by with the single "T" connection.

So then you could use one of the rubber "Y" vacuum connectors to branch off and somewhat separately supply vacuum to:
(a) the auto-shifting tranny control system, and
(b) the door-lock system(s) as presently plumbed.

In each the new and separate branches, you can add whatever size restricted orifice you find you need... and I would first start by restricting the vacuum drawn from the door-lock systems as much as you can and still have these locks perform reasonably well.

On the "Tranny-shifting" vacuum branch you might want to use the small neetle-valve idea someone recently shared with us on this THREAD. I still want to try this myself but I want to find the right needle valve that is small enough and has the needle tip tapered raw brass and now the rubber tipped type that are used to supply the ice-maker accessory we put on our refrigerators in the U.S. With such a adjustible needle valve, you could adjust the tranny-shifter system at idle until you get the lower vacuum reading you need where the VCV and Modulator lines come together. I trust you fully understand that there are different style VCVs but to my knowledge ALL are adjustible to some degree... and what you are doing is increasing/decreasing the tension/compression on an internal coiled spring that is acted upon by the VCV's mechanical link to the Injection Pump's (IP) throttle linkage... thus the VCV helps to increasingly "BLEED-OFF' the vacuum being seen by the Modulator. I LOVE run-on sentences... I write like we talk!

I hope this helps... and I'll continue monitoring this THREAD/Subject so his us with any more questions you have.
Regards - Samuel " MILLSAPS " ross !

Thanks for your answer Would I be right in assuming that we are dealing with negative pressure here ie suction therefore the wider the opening the lesser the vacuum at the guage ? I have a spare brake booster hose so have some room for experimentation, how likely is it that by drilling out the tee section my reading will reduce, what size drill bit would you reccomend? as far as the locking secton goes the yellow valves are non return right ? so with minimal leakage on that side the resevoir will fill and stay full enough of vacuum to still operate the locks regardless of the desired drop in vacccum for the tranny ? as concerns the needle valve suggestion I am not sure where to get such a device, does this act as an extra bleed or is it just a tap which increases the vacuum when locked down,Would a syphon tap such as you might use for beer making work? again I assume the smaller the gap the bigger the increase on the guage, look at me I am writing very long sentances now thanks again

Felix

There needs to be some futher tests before you go off and start randomly changing orifices.

First, does the vehicle have a vacuum control valve.........white plastic valve at the rear of the IP.........controls vacuum to the transmission?

If yes, please disconnect the hose from the top of the valve and connect the Mityvac. Pump up the Mityvac (engine not running) and record the reading at idle. Report back with results.