My 240D auto box flares (over revs) between changes and the car is pretty slow.
I need to check out the vacuum system but I cannot find a diagram which resembles mine - anyone got one?
I know I need to look at the VCV and modulator. BTW, the car has 75k miles from new.
If you look at the attached photo, you can see that the VCV cannot be removed and the only adjustment is via the two bolts in slots. Most posts talk about removing the VCV but I simply can't. Any ideas or is the adjustment done by turning the housing?
thanks - I am quite sure this is simpler than I think. From what I can see the VCV has one vacuum pipe going in with full vacuum and another coming out and these both go to the switchover valve which than has one going to to the modulator - simple. Am I right on this?

Attached Thumbnails

 

You have an "M" pump on your vehicle. Is this a Euro? Instructions for the US-style cars with the "MW" pump likely won't be applicable to your vehicle. Adjustment to the VCV is done by turning the body. Have a helper press the accelerator to the floor, loosen the 2 bolts and allow the body to flick CCW. Turn it CW until you feel resistance then tighten the bolts. There should also be a restrictor orifice going into one of the inlets that seems to be missing on yours. Without the restrictor orifice, you'll get way too much vacuum and flaring/slow shifts will certainly be a result.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Indeed this is a Euro car.
Thanks for your rapid, concise and logical reply - much appreciated after a long search!
I will do this but am going to do a diesel purge first. I will keep you posted. I think it could be out of whack because some time ago I took the car to a Bosch specialist to get them to change the gasket between the pump nd the engine and I suspect they are not vacuum specialists. We shall see.
Thanks again

Yes, it is.
Could you post the VIN of your car?

Thanks

WDB12318312013266

If that doesn't work. I would move onto the the modulator on the tranny next.

You can either search for modulator adjustment and do it the right way and make a whole weekend out of it.

Or you can just move the key clockwise one knotch. Put the cap and oring back on and go for a test drive. And just keep moving it one knotch clockwise until the flare is gone. Just remember to keep track of how man clicks u turn in, which way, and how where u started

Clockwise - less flare (more pressure) counter clockwise - more flare (less pressure)

__________________

I adjusted the VCV but it didn't snap CCW and the resistance was roughly the same all the way CW - not as though I hit a point of resistance. I haven't driven it yet since I want to do the purge first. Does this resistance issue mean anything to you?
thanks

Ur really gonna have to drive it to find out in my opinion. My experience with tranny tuning is do a small change, drive it and check, and repeat.

Im my experience aswell the VCV has only fixed fine tuning issues. But it's hard to tell how bad of a flare you have online so your issue very well could be a fine tuning issue.

What are your shift points at, at the moment? (What mph)
And does you car have a Bowden rod? Or does this model not have one?

__________________

See schemes & attached files.
The WDB12318312013266 has M/RSF injection pump & 722.117 automatic gearbox.

Attached Thumbnails

   

Attached Files

	27-003.pdf (263.2 KB, 74 views)
	27-340.pdf (91.3 KB, 77 views)

And table with shifting points. See 2nd variant.

Attached Files

27-330.pdf (22.5 KB, 65 views)

Could you point me to where the restricter orifice should be? I am referring to the one that you said seems to be missing. I am getting nowhere adjusting this..

thanks

I should mention that the vacuum pressure going to the box is around 10 ins at idle and increases to 14 ins at full throttle. Very wrong. The vacuum pressure at the T junction directly out of the vacuum pump is 23 ins

A couple of years ago I took the car to Bosch to fix an oil leak from the injection pump gasket. It was fixed and the car ran OK but the gearbox was still an issue. I drive the care almost never as a result but since it now needs a test I decided to dig into the problem again.
Guess what. When if finally found a vacuum diagram which is exactly right for this car I found that the two pipes from the VCV to the vacuum switch had been swapped - presumably by the garage!
So, instead of having maximum vacuum at idle and then a drop to almost zero under acceleration, I had about ten inches at idle and then by adding to this the minus 22 under load, you get around 12/14 - which explains the original readings! Thanks Bosch..

The way this works normally is that you have high vacuum and when you kick down the white swap over valve on the cylinder head shuts down the full vacuum and supplies the lower vacuum output of the VCV and thus the modulator changes gear downwards.
I will write a full document with photos if I works fine on this afternoon's roadtest