ALDA removal and retaining decisions. - PeachParts Mercedes-Benz Forum

dude99 · #1 07-13-2015, 04:47 PM

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

mannys9130 · #2 03-10-2016, 01:10 PM

Quote:

Originally Posted by dude99

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.

Dan Stokes · #3 03-10-2016, 02:25 PM

Quote:

Originally Posted by dude99

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

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

Jarod · #4 03-10-2016, 04:57 PM

Quote:

Originally Posted by Dan Stokes

An oversimplification but basically the ALDA adds fuel when under boost so removing it takes away fuel under boost.

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.

vstech · #5 03-13-2016, 11:13 AM

Quote:

Originally Posted by Dan Stokes

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

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...

dude99 · #6 03-10-2016, 08:32 PM

Quote:

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

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.

Quote:

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.

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...

mannys9130 · #7 03-10-2016, 10:40 PM

Quote:

Originally Posted by dude99

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.

dude99 · #8 03-10-2016, 11:11 PM

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

dude99 · #9 03-10-2016, 11:14 PM

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

mannys9130 · #10 03-11-2016, 10:41 PM

Remove yours. Let others keep their ALDA intact.

It's beneficial, designed there for a reason.

dude99 · #11 03-12-2016, 01:14 AM

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.

imryanmoriarty · #12 03-12-2016, 02:27 PM

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

shertex · #13 03-12-2016, 06:01 PM

Quote:

Originally Posted by imryanmoriarty

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

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.

imryanmoriarty · #14 03-12-2016, 08:09 PM

Quote:

Originally Posted by shertex

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.

Quote:

Originally Posted by dude99

Taken from STD:

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.

shertex · #15 03-12-2016, 09:12 PM

Quote:

Originally Posted by imryanmoriarty

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. OM603 ALDA removal instructions