Hello everyone I have been doing a lot of research on the transmission's reliance on the vacuum system because my 82' 240D started having flare ups on the shifts from 2-3 and 3-4. One worry I have is how long can I drive with these flare ups before it should be a concern? The only time I have is on the weekend and it worries me that I may be running the engine very hard. I have to really push the pedal down to get her to shift. When she shifts I can let up the throttle and settle her down. The same thing happens with the shift from 3-4.

The 2-3 shift flare up happens at around 33 mph.
The 3-4 shift flare up happens at around 55 mph.
Each of these shifts are soft.

I know the culprit is the vacuum. I have a vacuum gauge but I am going to purchase a mityVac to test everything. I have also heard that if I spray carburetor fluid or some other fluid around the hoses and whenever the idle revs up that is the general area where the leak is at (I think that is right but I want to check it through the mityVac for the experience)

Since my door locks have been acting up I am going to plug up the vacuum lines to the doors to try to isolate the problem in the door lock system.

She doesn't want to turn off on me after I have been driving around town never really going above 45 mph, so I have to turn her off manually using the stop lever. The thing here is I have to rev up the engine before pushing in the stop lever and the engine will cut off. This is another concern of mine, when should this be a bad thing?

There are a few things I know I have to do.
1. Check all vacuum lines and the main line should pull around 10-12 in. and should be zero at full throttle.
2. Make sure my T connector orifices aren't clogged.
3. Replace old hose connectors and hoses
4. Check vacuum diphragm
5. Replace shutoff valve
6. Replace Vacuum Valve : 3/2 Way
7. Adjust VCV and transmission modulator.

Is this right? What should I do first? How worried should I be? Is this thread too long? Hope I covered it all and thanks for all your help and the information that I have learned about my 82' from this forum has been amazing.

All comments greatly appreciated

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'82 240D
Currently running diesel but eventually I will French Fry her

Usually, vacuum leaks cause harsh shifting. But your other symptoms of shut-off problems definitely point in that direction.

Probably first would be fluid level. These cars seem to be very sensitive to this. Also bowden cable or shift linkage might need adjustment. Try here for checks and adjustments of the tranny:http://articles.mbz.org/transmission/adjust/

Hmmm, rev the engine before the stop lever works? The stop lever is a mechanical linkage on the IP. Maybe it needs adjustment?

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks Sam

I'm going to give this a good look over.

I've also been looking at the Steve Brotherton article on the transmission and vacuum system pretty closely too.

I was still wondering if continuing to drive with my flare up condition is bad for the engine and how long can I do this until I should be concerned. Hopefully I can track everything down this weekend and have some replacement parts by that time as well.

Thanks again

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'82 240D
Currently running diesel but eventually I will French Fry her

Now that you have indicated there are other vacuum problems, I would either:
(1) Solve the other Door-Lock problems first and to do this you might start with my POST " W123 Vacuum DoorLock Diagram " at:
W123 Vacuum InterLock Diagram. Let me know via P.M. & I'll send you a quality copy of the diagram. OR
(2) Plug up the vacuum line to the Door-Lock system while you trouble shoot your tranny shift problem.

Funny, I don't remember contacting you before... must have been via this FORUM's P.M?? Altzheimers setting in I guess!!
Sam

Oh SD Blue's signature is Sam as well but I am definitely familiar with your Posts Samuel Ross because they have been most helpful.

Thanks for the info I don't kow when I will be able to get to work with an ample amount of time but I will try as soon as possible. I think I will definitely plug up my lock system to isolate the tranny problem and my door lock problem.

I will post as soon as I get some results

Thanks again

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'82 240D
Currently running diesel but eventually I will French Fry her

I could be wrong- but i would not do the carb cleaner thing on a diesel- it works fine with a gasser, but i dont think it will work at all on diesel- also a chance of causing a run away engine.

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1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

This procedure is for gassers, where the vacuum is created in the intake manifold. It won't work on diesels, where the vacuum is generated by a separate engine driven pump.

Since the pump is not part of the combustion process, it won't cause a runaway. On a diesel, about all it does is waste carb cleaner.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks guys I will definitely not do that

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'82 240D
Currently running diesel but eventually I will French Fry her