I think I would just remove it before I tried to repair it.

Not a good decision. The ALDA plays an important role in fuel regulation and it shouldn't be removed.

Tried THAT mistake on Mutt the Race Truck. It really doesn't work. An oversimplification but basically the ALDA adds fuel when under boost so removing it takes away fuel under boost. Taking fuel away from a Diesel is NOT the way to make more HP. Fix the ALDA and work with it's range of adjustment to get a good seat of the pants feel - unless you have access to a dyno so you can adjust for max HP (preferred).

When I removed mine I didn't properly understand the ALDA's function so I followed the on-line "wisdom" which in this case proved to be wrong.

Dan

I was under the impression the ALDA limited fuel off boost.
I've removed several, and when the little rod is pushed down (as it would be by the aneroid capsule) it severely limits power, but if the rod is extended upwards (its been spring loaded on all the pumps I've pulled them off of) then you get full fueling off boost, which in every car I have makes a slight puff of black on a full throttle acceleration from a dead stop, slightly better off the line and no difference on boost.

Also, on my grey car it would not idle well when cold, I had to hold my foot on the throttle to keep it from stalling, removing the alda eliminated this.

As a note, my "removal" consists of removing, disassembling, taking out the lower aneroid capsule, reassembling and installing back onto the pump, plugging the inlet and routing the boost line to a gauge.

Perhaps you have run into a different setup than I've had on my 80 and 82 617s.

False. The ALDA is there only to limit the rack off-boost to prevent leaving a black cloud if you stomp on it off the line. You can mitigate that with your right foot.

The alda doesn't add fuel as some people think.

Interesting, you are the first person I have come across that has had a negative affect from removing it... I honestly can't see how thats possible...

3 people say removal is a bad idea and provide evidence for why that is so. Dan has accurate drag time measurements for quantative data.

Consult every thread about the ALDA over at superturbodiesel if you don't believe me.

But just to get the ball rolling:
ALDA removal advantages??? - Mercedes-Benz Forum

Remove yours. Let others keep their ALDA intact. :) It's beneficial, designed there for a reason.

Like I said, te reason was to prevent black smoke pre boost. That is useful to some and not to others. Just because it was originally deigned that way doesn't mean it's the best way. That's why I mentioned the option of removing it in the first place.

Not to further hijack your thread, but how exactly does one go about deleting the alda properly?

Taken from STD:

Loosen the lock nut and simply remove it...then plug the pressure line that was attached to it. Some like to put a cap on the IP where it was...but probably not necessary.

Ah, so the locknut above the ALDA housing is just to lock the adjustment screw in place?

And the large hex nut under the housing has female threads and fastens to the male threads of the housing itself?

Am I understanding this correctly? Next time I'm in a junkyard with one I can screw around with it, but the MB parts diagrams are pretty unclear and there isn't much FSM documentation on the ALDA.

Yes, yes, and yes. Make sure you take to the junkyard a 24mm wrench and a 27mm wrench. Sometimes they are a pain to remove.

See this for details. http://www.peachparts.com/shopforum/diesel-discussion/69422-om603-alda-removal-instructions.html

The answer to my question in the other, nearly identical version of this thread is sadly no.

Cool, so the ALDA is the same for 617 and the 603? Awesome, thanks.

This is incorrect.

The ALDA reduces fuel prior to boost. Removing it provides maximum fuel at all boost levels without reduction.

that's why it smokes if you floor it with the ALDA removed. Wastes fuel and if the wastegate seizes melts your engine...

Sooo... what was the question? And WHY would you post a question less answer in a thread?

I'm not sure I follow.

I think that the implication is that removing the ALDA is not proper, therefore the question invalid?

Where I agree with this in principal, I really don't care whether people decide to remove their ALDAs, provided that they know that there is some risk of overboost if the wastegate fails, probably a puff of smoke at the drop of the pedal without it, and a potential for reduced fuel mileage around town (stop-start on/off "throttle" driving). I feel no need to chastise you or tell you that your car will explode without it.

On the upside, removing it will restore off-boost launch without actually adjusting or repairing the ALDA.

I'm currently running adjusted ALDAs on both 603s, have on several 603 and 602 turbos in the past, and have no complaints about the performance of these engines with proper adjustment. If the ALDA is functioning properly and turned a bit rich, the max. fuel flow internal to the pump significantly affects the amount of enrichment available anyhow, even at 600rpm. There are people like GSXR, Sixto, me, and others who have tried it both ways and with turned-up IPs, and found that running an ALDA is not an impediment to power output.

The ALDA won't ever impede power if it's properly adjusted. Lots of people don't understand that, and they want to delete it instead of spend some time and dial it in.

I guess it's a philosophical difference.

Personally I'd rather take the time to remove an unnecessary layer of complexity and the maintenance it requires than properly maintain it.

"Is the dark side more powerful? "

"No! Quicker, more seductive the dark side is..."

lol, I love it

I got a turbo converted OM617.912, the IP replaced with a turbo one manually set "just right". The ALDA has never been connected. Here's a vid Dieselmeken made when servicing my car: https://www.youtube.com/watch?v=6DWfLImDFgY

So how does one adjust the wastegate to get maximum boost on a kkk turbo and then dial the alda in on my 85 300 SD 617?

There are several threads on this in the diesel performance forum, this one is a good start: http://www.peachparts.com/shopforum/diesel-performance-tuning/290694-om603-semi-super-pump-testing-fitted-bosch-6-0mm-elements.html

In this thread GSXR had worked with turning up a KKK, but had limited success due to the design of the turbo. Still, it can be done and if you have increased fuel flow to use the additional air, you can add a small amount of power to your stock setup and a noticeable amount of poke off the line.

This thread is 603, and there are many more threads in the Diesel Performance Tuning forum for 617s, but the ALDA and KKK turbo are of the same basic design.

I've personally never had my hands in a 617, but threads here outline how to check and clean the ALDA plumbing from the banjo-bolt to ALDA as a first step, then move on to checking the ALDA for pressure leak and adjusting, and of course a boost gauge to check for proper turbo/wastegate operation would be next.

603 Motor - ALDA Adjustment
 

I solved my doggy low rpm (pre turbo spool) performance by simply removing the adjustment seal and turning the adjustment screw one full turn. I started with 1/4 turn adjustments. I notice no difference in higher RPM performance.

For years I didn't want to mess with the seal thinking it might help the value (i.e. "original" factory set) or some silly thing. Then I found an alda at the PNP with the seal intact that I could use later if needed.

Proceeded with the screw adjustment and now have decent get up and go performance. No smoke screens etc.

Try it...you'll like it!