PLEASE READ A FEW POSTS DOWN FOR INFO ON FIXING A BROKEN ALDA


I finally decided to break the cap on my ALDA and turn it. What made me do this? My 300D nonturbo is much faster than my 300TD turbo off the line and up to about 20mph... that couldn't be right. I started by turning the screw ccw one turn - I test drove it and it was amazing! Then I got greedy and turned it more, and the screw came out. I tried to screw it in all the way as a baseline but then I think I broke something inside because now no matter how far in or out the screw is the car is REALLY slow. What's the matter with it?

I've decided that I did break it, since nothing else could make it act this way (am I wrong?). Now the question is, can I rebuild my ALDA, or do something to make it work again? I was thinking that putting shims under it might help...

It is not uncommon to break the Alda.. I did exactly the same thing. Unfortunately, there is no way to rebuild. I went to a bosch diesel injector shop to try and buy the part which was available. However, it was $600!!

Mercedes does not have a part number for the Alda because it comes with a rebuilt injector pump and they claim the pump is calibrated with the ALDA.

The best bet is to find a used Alda which is what I did. I simply put the new one on and wahla!! worked like a charm and all was back to normal. I have a spare that I may part with but I'll have to think about that first.

Thanks for the reply. I went and checked out a local junkyard and the only MB diesels I found were non-turbo, so they had no ALDA. Let me know if you can sell me your spare, but for now I'll keep looking.

ATTENTION: A broken alda can be fixed! Or at least, you can do something to make it work again.

My alda broke, as the result of too much playing around with it. The screw didn't seem to do anything anymore, it just goes in and out.... and the car is stuck in a mode that is really slow. You DON'T need a new alda, just use the "shim" method to adjust the alda, and you can get it back to a good setting. Although you might have to take the alda off and put it back on a few times to get a good setting, it's better than buying a new alda. My alda was never broken... it was just the adjusting part that was broken. By adjusting a different way I was able to get around the problem and save money.

For those of you who don't know, you can adjust the alda in two ways, 1) tinker with the screw on the top (ccw giving more power), or 2) put a shim under the alda to raise it a little bit (raising gives more power). 1.25mm shim = 2 turns ccw of the screw. As a shim, I used a perfect-size washer I found sitting around, it was about 1.5 mm thick. My car is fast now!

Hope this helps.

Sorry for my naive question, what is an ALDA?
Can you post picture of the adjustement side?

The alda is on top of the injection pump, directly to the driver side of the engine block. I've attached a picture of an alda, where to find the screw.

And where to put a shim (as a shim, use a washer or some kind of spacer):