Hello all,

I have a 1987 300D Turbo that's a bit slow to shut down...I have also noticed that it doesn't seem to be shifting (automatic) quite properly.

Do these events have a connection?

Upon a quick inspection under the hood, I found no vacuum lines disconnected.

My first thought would be the vacuum fuel shutoff in the injection pump...Is that difficult to replace?

Any suggestions would be appreciated.

The Tenor Man

Try capping off (one at a time) the climate control vacuum lines, and the door locks.

Those tend to leak a lot.

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

I had a leaky vacuum actuator in the coupe's passenger door. The car started not shutting down when the vacuum leak got bad enough.

And yes, vacuum leaks could affect shifting if bad enough.

One thing I noticed was that the system would build vacuum and behave normally when the doors were locked. But in the un-locked position it would not hold vacuum.

So, Out with the Mighty-Vac, which I used to test vacuum circuits from under the hood. Found the reservoir to be good. Confirmed the leak when the doors were un-locked.

I then removed the driver's door panel so I could access the lock and un-lock circuits at the switch in the door. This may have been un-necessary, but it did allow me to verify that the switch itself was not leaking.

I by-passed all the trunk actuators and still had the leak, which localized it to the door. Opened the door and found the rubber boot on the actuator's rod to be cracked.

I scored another actuator from a '84 sedan in the scrap yard, installed, and all is well again. I noticed that MB changed the design of that boot, and also upgraded to a silicone-based material that won't crack as easily.

The idea is to find which system leaks, and then remove devices from the system to localize the leaky item.

Hope this helps!

__________________
- Greg -
1973 220D, The Prodigal Benz
1974 240D

Sounds like a vacuum issue with both problems related. I don't know how the vacuum system is set up on non-123 cars. Shut off valve is not hard to replace on a 617 but the problem is usually elsewhere in the system on 123's. A quick test is to put a Mity Vac or your lips on the vacuum line to the shut off valve, pull a vacuum and see if it shuts off promptly. If it does, the shut off valve is ok and you have a leak elsewhere.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I was under the understanding that on the 124 chassis, the door, trunk and fuel door vacuum system was operated by the vacuum pump under the rear seat. If so, I could rule out the locking system as the culprit.

I thought that the climate control and engine vacuum was getting its vacuum from the main pump on the front of the engine (which I upgraded to the latest version in July, 2007).

Anyone know?

Thanks,
The Tenor Man

__________________
Currently Driving.....
1987 Mercedes Benz 300D Turbo - Daily Driver.
2004 Buick Rendezvous...Smaller than it looks!
2005 Mitsubishi Galant - Not bad for a tin box...Lousey Seats
Past Vehicles.....
1994 Dodge B-250 Van- GAS HOG..Succumbed to rust!
1989 Mercedes Benz 260E - Totaled but no one injured.
1977 Mercedes Benz 240D - Loved it, but SLOWWW! - Succumbed to RUST!
1976 Mercedes Benz 240D - Same as above! -
1975 Mercedes Benz 240D - Same as above!

You are correct, sir, although I'm pretty sure your pump is in the spare tire well of your trunk - unless you have a wagon. 123s are quite different from 126s and 124s in this respect.

__________________
1998 E300 +310,000K
1996 E300 +460,000K

You are correct on all counts Tenor, and yes, the pump for the door locks (and orthopedic seats if installed) is under the RR seat on the wagon and sedan 124.

- Jeff

__________________

Gone to the dark side

- Jeff

Tenor, There are several possibilities, but it would appear that the root cause of your issue is VAC. improper vac to the shut-off valve will cause a your delay and improper shifting. Some of the possibilities include, the check valve (black and white plastic piece located on the drivers side near the fire-wall) or the connecting vac lines. or even the shut off valve itself. unfortunately the engine vac system is all tied together, so in reality the leak could be elsewhere.

Do you own a mighty vac tool?

This could help you track down any leaks

__________________
Dean

FWIW the temp gauge for the EGR on mine was the cause of a very hard to find vac leak.
-nB

__________________
'83 300D Turbo
Current: ???K mi - 19.2mpg -> 17.4mpg -> 22.9mpg ---> ODO Died
bought at: 233.8K mi - 10MPG For $1.00
3.5 cylinders work: 320 320 100 340 280
Got insurance? FarmersReallySucks.Com

Thermal vacuum valve, maybe??

__________________
Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



TRUMP .......... WHITEHOUSE
HILLARY .........JAILHOUSE
BERNIE .......... NUTHOUSE
0BAMA .......... OUTHOUSE

Something like that. It went EGR -> this thingy -> black box on valvecover.

__________________
'83 300D Turbo
Current: ???K mi - 19.2mpg -> 17.4mpg -> 22.9mpg ---> ODO Died
bought at: 233.8K mi - 10MPG For $1.00
3.5 cylinders work: 320 320 100 340 280
Got insurance? FarmersReallySucks.Com