Does anyone know what this vacuum (?) valve is for?! The car supposedly has had this valve disconnected by the previous owner... see the pic below plz. Is that something that used to hook to the EGR valve?

The car is a 1987 300SDL...

Attached Thumbnails

 

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

Without the line connected, you'll have no boost enrichment below about 2600 RPM, making the car perilously slow off the line. It doesn't "hurt" anything, but it's far from correct.

It's not a VACUUM line, it's a pressure line.

Sorry about the spastic photo editing--tried to make it smaller (for disk) but preserve necessary details.

Attached Thumbnails

 

__________________
James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

I know about ALDA on my 1985 300D and if it's not working the car ain't going anywhere until you reach 2000 rpm and then it takes off...

I've read however, that you COULD remove the ALDA all together and still be ok... it seems in this case the ALDA is gone all together... what does that mean then?!

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

It attaches to the nip directly above ALDA. A "splint" would only be about 4.5" of vacuum tube (borrowed from EGR?). However, you won't have overboost and cold-start torque reduction; ALDA probably doesn't work anyway without an adjustment at this point.

See GSXR's sweet rightup on help for a 603A ALDA. You will need a 27 and 30 mm wrench for superEZ (tm) tuning.

__________________
James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

How about this post from Brian Carlton on the subject of removal of ALDA - it seems that this car has had the ALDA removed - which is precisely what Brian and others advocate....

http://www.peachparts.com/shopforum/showthread.php?t=162744&highlight=removing+ALDA

I'm going to read the whole thread - will take me some time - it's a long one but I'm feeling a bit better about it than a minute ago...

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

If the vehicle already has the ALDA removed, you've got nothing to concern yourself with other than possible black smoke if you mash the pedal.

Also, be understanding of the fact that you have no overboost protection..........if the wastegate sticks closed, or the wastegate hose fails, the engine will get excessive boost pressure and possibly damage the head gasket.