replacing alda on 6 cylinder Mercedes - PeachParts Mercedes-Benz Forum

1987300sdl · #1 10-24-2007, 06:55 PM

I have read some articles on how to adjust ALDA on Mercedes.
I tried adjusting it, but might have made it worse.
My car is sluggish on acceleration. It gets better as the engine gets warmer.
As the RPMs gets high, the emergency fuel shutoff lever shuts off the fuel, and starves the engine. I replaced the engine overrev, and it was much better for a while, but then started acting up again.
I have also adjusted the ALDA, and am wondering if I messed it up.

What does the ALDA do??? What is its purpose??
Is it a type of a mechanism to adjust the timing???
Does the ALDA effect the Fuel Shutoff???
If I replace it, do I have to have any special equipment to adjust it??
I have one that I acquired, but the 'can' has also been broken off of it, and I dont have a 'starting point', so I dont know if it is specific for each engine or not. I also dont know if it has been previously adjusted.

Any assistance is appreciated.

Jeremy5848 · #2 10-24-2007, 08:21 PM

Your questions have all been asked and answered here many times before. Use the search function and you will find them. For starters, try this thread:

http://www.peachparts.com/shopforum/showthread.php?p=1655884

bustedbenz · #3 10-24-2007, 10:50 PM

Every thread I have found talks about simply removing it. Supposing someone were insane enough to ignore good advice and take their ALDA off, discover that it was bad (yes, ours is), and want to put a working one back on, properly adjusted, instead of leaving it off entirely. Where does one get a replacement if one were so inclined? That's one that I haven't found in a thread yet. They're all keep it on vs. take it off completely.

Brian Carlton · #4 10-24-2007, 10:59 PM

Quote:

Originally Posted by bustedbenz

Every thread I have found talks about simply removing it. Supposing someone were insane enough to ignore good advice and take their ALDA off, discover that it was bad (yes, ours is), and want to put a working one back on, properly adjusted, instead of leaving it off entirely. Where does one get a replacement if one were so inclined? That's one that I haven't found in a thread yet. They're all keep it on vs. take it off completely.

They are on e-bay every so often, or contact Speedy300Dturbo on this site. He'll get you one.

#5 10-25-2007, 06:20 AM

Quote:

Originally Posted by bustedbenz

Where does one get a replacement if one were so inclined?

Used through an individual/parts yard or included with the purchase of a new injection pump.

When you adjusted yours, did you break off/twist out the adjusting screw?

bustedbenz · #6 10-25-2007, 02:29 PM

No, we have not even tried adjusting it. My dad took it apart and found that it was defective inside. Said it leaked and he couldn't convince himself that the metal bellows inside was actually holding air. He's two hours away at home right now, so I don't really know what he did. He just told me he took it apart and it wasn't ever going to work right. Thought he might be able to rebuild the seals and things but wasn't sure the bellows was working. (or diaphragm or whatever's in there)

I'm running without it right now.

gsxr · #7 10-26-2007, 06:10 PM

You can't test the ALDA on the b ench. It has to be tested, WITH PRESSURE, not vacuum, while mounted on the pump. If it's been taken apart, it may need sealant between the two halves, and it may also need a new shaft seal. A good one will hold 10-15psi and either not leak down, or leak down slowly. If you can't pump it past zero with a Mity-Vac, the seals are bad. The aneroid capsules (metal bellows) are fine unless they are cracked, broken, or have the top threaded shaft broken off. Some links:

http://articles.mbz.org/engine/diesel/alda/

http://www.w124performance.com/images/OM603_injection/

Yours will probably be fine with a new shaft seal (if it even needs that). Or buy a used one from Speedy, he tests them and only sells good ones.

bustedbenz · #8 10-26-2007, 10:35 PM

We definitely need that shaft seal, is it available from Phil or somewhere?

gsxr · #9 10-27-2007, 12:43 AM

Quote:

Originally Posted by bustedbenz

We definitely need that shaft seal, is it available from Phil or somewhere?

Nope. The only way I know of to obtain them is from Jim Friesen of the old Mercedes email list - he had a source for a seal that worked perfectly, and was selling them pretty cheap. Try a Google search, or maybe see if his email (jfreezn *at* aol dot com) still works. If you can't get a hold of him, drop me a line, I *might* have a spare I could sell.