During research into the subject, I came across one posting (elsewhere) referencing an adjustment to the ALDA by placing a washer underneath the ALDA unit. This seems logical, in that it would effectively raise the fuel control rod, but without the danger inherent in turning the calibration screw & possibly breaking the aneroid chamber.

Questions:

Has anyone heard of, or actually done it this way?

If so, what thickness of washer would most likely be the best to start with?

Third, what is involved in removing & reinstalling the ALDA unit from the IP? (is it just a simple ‘drop in’ or is there an internal connection to deal with?)

Many Thanks Everyone!

Running too hot,
Under the ALDA there are washer(s) of different thickness.
You can change them, but be carefull or you will get the car running too rich and really smoking. Here in Ky. the police will stop you if your car is putting out too much black smoke. Ask my friend Dana.
Bill Lewallen;Lexington,Ky.
Home of RDC Bearings...

Thank You Wm. Lewallen
 

Thank you for the info! It seems that this method would really be preferable to the potential damage caused by the adjustment screw. I wonder why no one else seems to bring this up? (rhetorical question :) )

Do you happen to know approximately what thickness of washer should be added that would equate to one turn on the adjustment screw? Also, are the washers a specific (read: strange, or MBZ specific) diameter, or can they be sourced from a typical auto parts or hardware store?

Thanks Again!

Running too Hot,' All the other experts didn't know they were there. To get to them;Cut off a 27mm and 24mm leaving about 6" in the open ends.The 27mm holds the bottom,the 24mm part will turn the ALDA off.
Bill Lewallen; Lexington,Ky.
Home of RDC Bearings...

Before you go running out twisting things I thought I'd chime in. I own two 300SD and have adjusted both with no problem. I have also gone to the local u-pull it yard and scavenged up a few spare ALDAs. Inside are two well constructed brass diaphragm chambers. They look very tuff. I have removed and inspected over a dozen ALDAs and have yet to find more than one thin copper washer. ( I found the same thread you mentioned while contemplating making the adjustment) One car is adjusted full out with the boost at 14psi and smoke is all but undetectable (only visible in following head lights at night) The other is 1 1/8 turns in and smokes lightly under full throttle.

To remove the ALDA I have had success with a medium sized crescent wrench and a firm grip on the ALDA. The large nut underneath is captured on the IP, turn the nut clockwise and support the ALDA with your free hand. Do not allow the ALDA to turn too far and damage the plastic vacuum control valve

I hope this Helps, I say go for the gusto and turn the little screw out.

Bob D.

Well, I bit the bullet and adjusted the Alda in the ‘conventional’ manner. Thanks guys for all the support!

And H2O – 14PSI boost? How long have you had it set at that pressure? Any indications of an impending melt-down? I’m sure it must run like a scalded dog! Well, maybe a scalded three legged dog with arthritic hips, this being a diesel, after all :) .

Thanks Again!

Hot,

Glad to hear you took the plunge. It generally take a few tries over a few days to get it just right. Look for a faint wisp of dark smoke in the rearview during full acceleration under full load in full sunlight.

I can't site the source to you as I lost all my links and saved articles during an OS upgrade error, but I'm very sure after extended research that 15 psi was the safe limit. The over boost protection solinoid opens at 1.1 bar which converts to 16psi.

Getting the spring in and out to adjust the boost is a buggar but well worth the effort.

Bob D.

[Edited by h2odiesel on 06-23-2001 at 08:51 AM]

Ok, now it's my turn. I got brave and did the adjustment which was a cinch. I found 2 washers, one 1.5mm thick and one paper thin. I added one 1.5mm washer. Any ideas as to how much one should add. How much should I notice with the addition of the washer. I did notice a slight amount more smoke and power. I had already adjusted the boost. Do I dare add another or will it iterfer with something?