As far as I know my ALDA operates fine. Low end power sucks turned CW and takes off quite nicely turned CCW, but poor fuel mileage turned CCW. So this begs a question. Why do some remove it totally? Is there that much of a power gain? I know that removal is a low cost fix for some with a malfunctioing ALDA. What are your thoughts?

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

Parrdon me for any ad-nausium debate on ALDAs

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

Take it off and see what happens. Obviously lower fuel mileage, but see if it performs any better than just the adjustment.

Depends on you. My SD would start from a stop in second gear, I though I was driving a 240 until the rpm went up.

I adjusted the ALDA and now it starts in first gear. I get much worse fuel mileage now.

That's the price you pay for performance.

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83 SD

84 CD

There are two reasons to leave it in place and functioning as designed and one reason to remove it:

The reason to remove it, as I have done on the 603's is as follows:

My belief is that the 603's generally suffer from less than desirable fuel quantities.........either from the factory........or due to age. Therefore, adjusting the ALDA to the desired point is impossible because the ALDA doesn't have sufficient range. After it's removed, the driver determines how much fuel to provide via his right foot. In the case of the 603's, it's very difficult to get them overfueled, even from a standing start. Therefore, the ALDA is largely superflous.

The two reasons to keep it in place:

1) Some 617 engines get plenty of fuel, and removing the ALDA will result in heavy smoke until the turbo spools. The driver can control the smoke by being judicious with his foot, but few people drive a diesel that way.

2) Without the ALDA, there is no protection from overboost. If the overboost protection solenoid is working and is tripped from a stuck wastegate, the ALDA is the device that eliminates the fuel and prevents damage to the engine.

I can concur with BC.

I have removed the ALDA from my 603 and a 617. 603 has no MPG issues at all! Power seemed to improve and I can finally pour some smoke if I need to assert my dieselness. The 617 power seemed to increase a lot BUT my mpg's have suffered because of it. All you have to do is train yourself to stay out of that pedal...

Actually my diesel driving style has really helped me with the 400E. You really have to resist the urge to "stomp" on the gas in that car. If you drive it like that it seems you can see the gas gauge drop.

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08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

Brian, I don't recall discussion about adjusting via the set screw vs shimming. Does the set screw merely shift the ALDA response curve the way shimming does, or does the set screw adjust the shape of the curve as well? I can't tell by looking at the innards of the ALDA -



Thanks,
Sixto
87 300D

I cannot be sure if any difference exists. From all discussions, the the set screw does the same thing as the shim.........a shift in the curve.

It seems to me that shimming is just pulling the ALDA away from the rod in IP and has same effect as adjusting the top of ALDA set screw.

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'85 300D Turbo - CA Version

So I have it adjusted to full enrichment. This week I will take it off for diag purposes to see if performance improves more. I know this: when enrichment was set to approx half, it was a dog, but had 32-34 mpg. Now that its adjusted to full, I am seeing mid to high 20s. And there is black smoke when romped on. So, I think I will take it off permanently id there is a significant increase from here, but I will adjust driving habits with the accelerator. Any need to worry about exhaust temp? I have seen some posts about installing a pyrometer.

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

Shim and screw are identical. When the pump is being calibrated the shims are used as coarse adjustment and the screw is fine adjustment.
As the vehicle owner, using shims allows the tamper-proof cap over the screw to remain intact for cosmetic reasons.

I think you have other issues amiss if you are seeing that great of a fuel economy swing with the ALDA removed. Mine has been off the SD forever and I still yield 22-24 city and about 28-30 freeway. Pretty much the same as when the ALDA was installed.

Also, I am not sure how you are achieving ~33mpg avg unless driving 55mph. I achieve 30-31 driving about 60mph on pretty flat freeway trips.

Are you certain your odometer is working properly? The one on my 300sel became slower and slower showing what I believed to be 5-7mpg... then finally failed.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

So, I belive I understand how to shim or adjust the set screw on the top of my ALDA, but when you removed the ALDA, what do you do with the linkages under it? My limited understanding of studying this in the Mercedes manual, is that for more fuel, the bellows pulls up on the linkage because the bellows "shrinks" under additional boost pressure. If the ALDA is removed won't the loose linkage act as if no additional fuel is needed?

What am I missing here?
Thanks,
Jeff

the alda pushes down on the plunger to reduce fueling. removing the alda, removes the reduction of fuel.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

vstech,
Thanks for the reply.

Ok, so the bellows is not physically "attached" to the plunger, just pushing against it?
Is the plunger contained such that it will not jam up if the ALDA is removed?
It appears that mine has a large nut built into the body which implies that it is screwed into place. Can it be removed without removing the intake on a 87 300D Turbo?
And lastly, does anyone know what shim thickness would give the same result as just removing the entire ALDA?

Thanks!
Jeff