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'84 300D/ dakota benz trk. Sold... miss it. "88 260E '91 190E 2.6 '89 Volvo 240DL "85 300D
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1,252 Posts
Discussion Starter #1
is there any advantage/disadvantage to removing the alda completly?
 

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1995 E320 Cabriolet
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126 Posts
None. Power will drop from 125hp to about 90hp, fuel consumption will increase.
 

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82 300D VNT, 80 240D 3.0T
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3,926 Posts
Maxbumpo said:
None. Power will drop from 125hp to about 90hp, fuel consumption will increase.
That is 100% incorrect information. I have done this modification myself and know the results.

Removing the ALDA will make the pump operate as though you have maximum boost pressure at all times. It will give your accelerator a more linear feel, there will be little or no boost rush in normal driving, MPG will NOT change, and smoke will only occur if you mash the accelerator from idle.

The only downsides are you will have no overboost protection and you *might* fail emissions testing for smoke. (Mine passed state emissions without an ALDA, BTW.)

Removing the ALDA applies to 82-85 300D/CD models, 81-85 TD's, all SD's, 87 190D 2.5T, 86-87 300D/SDL, 91-95 300(350)SD/SDL models, and 91-93 300D's.
 

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'84 300D/ dakota benz trk. Sold... miss it. "88 260E '91 190E 2.6 '89 Volvo 240DL "85 300D
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1,252 Posts
Discussion Starter #4
thanks. do you happen to have a step by step procedure for removing the ALDA?
 

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82 300D VNT, 80 240D 3.0T
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3,926 Posts
Remove the banjo bolt from the ALDA and plug it's line.
Use a 27mm wrench (or 1-1/16") on the bottom nut and a 24mm wrench (or channel locks) on the ALDA.
Turn the nut clockwise and/or the ALDA counter clockwise until the ALDA comes off.
That's it!

The shaft visible on the pump has it's own seal so no oil will get out or dirt in.
However, disassembling the ALDA, removing it's internal bellows, and reinstalling it as a dust cover is recommended but not required.

Once you remove the ALDA, the amount of accelerator you use for normal driving will change. As a result, it will be necessary to tune your bowden cable (shift RPM) and vacuum devices (shift firmness) to get smooth transmissions shifts at the desired RPM's. If you don't know how to tune your tranny, I can point you towards threads that explain it pretty well.
 

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'84 300D/ dakota benz trk. Sold... miss it. "88 260E '91 190E 2.6 '89 Volvo 240DL "85 300D
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1,252 Posts
Discussion Starter #6
so it did make a power difference when you did this? i wonder why it was ever installed from factory?
 

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82 300D VNT, 80 240D 3.0T
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There is no increase in power, if that's what you mean. There is the perception of more power because you are getting all the available fuel at once rather than being restricted until boost kicks in.

It's an emissions control device, just like the EGR. It prevents visible smoke out the tailpipe.

The same device found on Dodge's 5.9L Cummins is labeled "Smoke Control" in their service manuals.
 

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W-1-2-3 Go!
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16,161 Posts
Lance, do you know if you also have to adjust the wastegate when you remove the ALDA? Are you saying that by removing the ALDA, there will be no turbo lag? I know the turbo will still have lag, but how can you say that it will be more linear when you still have the turbo? I'm a bit confused.
 

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300SD
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11,191 Posts
I have trouble understanding this obsession with removing every control device on these engines. Replacing the injectors with new rebuilt ones, properly timing your pump, adjusting the valves, and fixing oil leaks will do a lot more for you than gutting the controls form the engine.

No offense, but a lot more diesel engine knowledgeable people than yourself designed these diesel engine controls and you are more likely to screw something up than improve on it.
 

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82 300D VNT, 80 240D 3.0T
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3,926 Posts
WeVonBraun said:
ALDA is analog
EGR is digital
Huh? Where did you get the EGR is digital part? It's computer controlled in 84+ models.

karugs said:
Lance, do you know if you also have to adjust the wastegate when you remove the ALDA? Are you saying that by removing the ALDA, there will be no turbo lag? I know the turbo will still have lag, but how can you say that it will be more linear when you still have the turbo? I'm a bit confused.
No need to mess with the turbo, it will still have the same boost levels. There will always be some turbo lag. With a functional ALDA, when you apply 50% throttle you are in really applying only about 40%. As boost builds, the ALDA allows the additional 10%. This is the rush you feel as the turbo kicks in.

Without the ALDA, when you apply 50% throttle you are actually applying 50%. No rush means less manipulation of the throttle and a smoother, more Mercedes-like acceleration.

p100 said:
No offense, but a lot more diesel engine knowledgeable people than yourself designed these diesel engine controls and you are more likely to screw something up than improve on it.
They designed it to meet the required emissions standards while remaining efficient and reliable. Removing the ALDA gives the car a higher quality of driving. Removing the EGR allows the engine to breathe clean, uncontaminated air. Significantly reducing carbon buildup, cylinder wall wear, ring wear, oil contamination, and intake restriction. All that at the expense of slightly higher NOx emissions.

I have yet to break my engine after 4 years of experimenting and tuning!
 

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1985 300D
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163 Posts
humm, this sounds like something i would like to try. i wonder if will help with the snail like acceleration i get in the mornings!
 

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1985 300 turbodiesel
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102 Posts
So..I was messing with the ALDA last night and as I approached 270 deg. of CC turn the wrench experienced increased resistance and in the next moment, the ALDA bolt was splayed/sheared off. Upon further messing around I managed to strip the threads inside the ALDA, thus preventing any further adjustment. I found this thread and removed that sucker and I concur that the acceleration is more linear than it used to be, my overall 0-60 time did not improve, but the car feels a little quicker off the line. Couple questions for you Zedd, lifesaver of a thread BTW as far as the removal goes, I did have to remove the injector lines, no big deal.


1. I left the banjo bolt and line from the rear of the engine/ intake and plugged it at the end that used to connect to the overboost sensor. Is this correct?

2. The car seems to accelerate and shift correctly, what specifically did you adjust, was it mainly a matter of lengthening the throttle linkage rods to uncompress the power band, if you catch my drift. It seems now that the rpm's increase more quickly with less foot. I could be wrong.

3. Do I need to be more careful with my lead foot? Am I putting my baby in danger of possible premature retirement? Did you notice, or can you see any way in which this would increase the operating temp. of the engine? It could just have been the 90+ temps. today but it seemed my temp gauge was edging a little closer to 100 C, after removing the ALDA.

I'll be anxiously watching my MPG, but so far I'm feeling pretty good about this.
 

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300SD
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11,191 Posts
FWIW, on my '83 300SD the ALDA screw has been turned out and the immediate throttle response from zero is a little better than on my '85 300D which still has a factory sealed ALDA adjustment. However, turbo spooling is much more impressive on the 300D and it feels better at speeds over 40 MPH. I recommend not messing with the ALDA at all, just keep the system clean.
 

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1982 300TDT&1984 230TE
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119 Posts
Zedd, what is the difference adjust the Alda to max[turn the adjustment screw counterclockwise ] or remove it definitive ?
Thanks
 

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82 300D VNT, 80 240D 3.0T
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3,926 Posts
1. That's fine.

2. Some cars my not need any shifting adjustments. It depends on engine/tranny wear and personal preference.

3. The only risks are overboost damage if the wastegate fails, lower MPG if you like to mash the pedal everywhere you go, and visible (black) smoke. Maximum fuel will not change so there is no additional risk of melting the engine.

Removing the ALDA vs adjusting the screw to max gets that extra little bit that the ALDA may be still be holding back.

It's a good idea to at least adjust the ALDA 1/4 turn CCW if it's still got it's tamper seal in place. The energy content in the fuel today is significantly lower than it was when these cars were built. Adjusting it will return the acceleration they were meant to have.
 

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1985 300 turbodiesel
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102 Posts
Zedd- Really appreciate the fast response, was freaking out a little bit, just drove to work, no problems, everything seems fine other than my door locks not working. Must've not plugged a vac line in my haste last night. One other question, does anyone out there know of a source for a decent used ALDA in case I decide to change my sinful ways. Would any one of you committed ALDA-less renegades care to sell me yours? I can't afford a whole new one right now, and I don't want that to be the determining factor in whether Gretchen has all her pieces.

Thanks.
 

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1982 300CD
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5,134 Posts
You'll be running rich until the boost kicks in. Black smoke is unburned fuel.
It's a slight waste of money and you'll need to clean the bumper now and then.
 
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