What is understood?

I meant in general, from Jack to others...

Good point! So what if it isn't in the repair manual? Guess then that means not to do it! Seriously though, I don't think I use the manual enough. With the Volvo I am scared to get the manual dirty and was REALLY upset when I did give it a smudge! So I will remember what you said and get out the bloody manual! Worse comes to worse I can always make photocopies.

__________________
Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.

How about you go back and read post #26 again...........maybe a bit slower this time.

I am not seeing a post by me in #26 claiming 14P.S.I., only you making a claim from thin air. Guess you must be a reporter... or like the media. Thanks anyways!

__________________
Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.

You might find it hard to believe but the world doesn't revolve around you.

I'm finding it hard to believe that this thread is being dragged down to the level of personal insult... but yet, there it is.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.

The A.L.D.A. has to be replaced. The screws are not coming out and sick of messing around with it. I spent a half hour using an impact driver with a heavy hammer and all I did was mess up the threads. Rather just get one that doesn't leak and be done. I could have saved the $30 for the impact driver and put it towards another A.L.D.A.. So if anyone has a leak free unit, please contact me.

__________________
Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.

To replace an ALDA unit, you likely are not going to be using any bits or attacking any screws. To replace the whole unit, you need to unscrew it from its base where it attaches to the IP. You will need a thin, open end wrench to remove it. You may find it necessary to need a second wench to hold the nut on the IP as you remove the ALDA. Don't mess with the flat head screws on the upper face of the ALDA if you are replacing the whole unit.

I suggest taking this time to test out your fuel mileage and performance changes while the ALDA is off. As I understand it, the ALDA is an altitude compensating device that also limits/controls fuel flow/delivery based on boost levels. Removing the ALDA will not over-boost your engine as boost pressure is controlled by the waste-gate. It will provide more fuel flow at lower RPMs and thus more boost, sooner. Nothing wrong with that. Let's say your waste-gate is limited to 12PSI of boost. The sooner in the RPM range you get to 12PSI boost, the better the low range performance will be. If boost was always at 12PSI, you would see very responsive pickup off the line but since that is not realistic on the OM617, you only have a few options.

Just like on my truck, over a certain boost pressure, the air is too hot and not dense enough to be effective. An intercooler will solve that issue by cooling the air and making it more dense at X PSI. For example, if you have 15 PSI of air at 250F, it is just as effective as 12PSI at 190F. (Not scientific or realistic values but for illustration purposes only!)

For stock specs, you are looking at a new/good ALDA and a well performing turbo coupled with a tuned, timed and adjusted vale and injection system. Costly, yes but it would go a long way towards restoring power to OEM spec. That or you can ditch the ALDA and limit the power with your right foot. Either way works well and both have low risk.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Thank you for the reply!

I am sorry it wasn't clear. In the last few days I have put on about 200 miles and a half tank of fuel (meaning about 20M.P.G.) without the A.L.D.A. installed. I like not having the A.L.D.A. for performance, but fuel economy is suffering. I have been careful with the throttle but doesn't seem to be helping. Since Mercedes specified it, I rather find a good used unit and adjust it to where it should be.

The A.L.D.A. limits fuel as the boost increases. That is why it should be adjusted until there is little or no smoke. Smoke equals poor fuel efficiency.

I love to find a new A.L.D.A., but as far as I can tell, it mean a whole new injector pump for $750! That is not going to happen!

__________________
Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.

Without an ALDA, what does your smoke opacity look like? 400 miles per tank is not bad at all. That I would consider very good on my 300SD with a stock ALDA installed. I adjusted my ALDA up a little but did not notice much difference. I am ready to take it off and see what happens. I have a lead foot, so I am sure I will see an MPG drop. Not really a concern for me if I keep using WMO for fuel. At that point, I really don't care about MPG. $1/gal for fuel negates MPG concerns for me.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Sorry, 400 miles on a 20.5 gallon tank is nothing short of miserable for a 300SD.

I can squeeze 600 miles out of the '84 SD if I were to bring some fuel with me (as a backup). 550 miles is the norm.

A well sorted vehicle that is driven properly with correct IP timing and with speed limited to 65 mph can always get 27 mpg and 500 miles on the tank.

If you're not getting it, the vehicle is not properly sorted or you try to keep up with the gassers for some moronic reason.

Edit: Let me add: I got 24 mpg US under those conditions.
.....

I have had the ALDA off my Benz for one tank full. My mileage was down but the weather was really cold for the first time with a lot of cranking, a couple of no starts and idling for about 90 minutes. I nearly religiously log the mileage on all four of my cars/truck and have spread sheets going back years. It might be until spring until I can tell but I should have some data to whether it can make a difference to my car.

I figure that using light throttle will be about the same as Having the ALDA in service. The way I understand the ALDA works is to limit the pump rack travel unless the conditions are called for. By injecting extra diesel early you can bring up the boost faster to a point. At the expense of fuel usage.

My ALDA is still functional and I could reinstall it if I find the mileage is actually decreased by not having it.

It gives me the option of having a faster power build up when I want it, say if I was passing (not likely, I am the typical old man driving an old Mercedes diesel, yes the days of my motorcycle road racing are in my past) or some other emergency.

__________________
85 Merc 300D - Unwinding 31 years of wear
86 VW TD
Mahindra Diesel
Iseki Diesel

In 2007 I didn't own a diesel.

The fuel economy cannot decrease when the ALDA is eliminated if you drive the vehicle in a conservative manner (1/2 pedal) below 2200 rpm.

The capability of the turbo to provide any significant boost below 2200 rpm is very limited, whether you have the ALDA installed or not.

If you need horsepower, you must wind it up, unfortunately.

That being said, it has quite good capability at lower speeds via the use of lower gears. What you cannot get from horsepower can easily be compensated with gearing at lower road speeds.

What the vehicle can never do is to provide significant acceleration capability in gears three and four below 2200 rpm. Even at 3000 rpm, it's acceleration is mediocre in high gear.

I guess I should fill my tank up and see what I am getting for MPG. I don't usually track my MPG but I did last summer. Maybe the A/C threw off the numbers.

I am pretty sure my IP needs to be timed. I get white smoke at idle sometimes and it smells fuel-rich. The IP probably needs to be advanced a few degrees and or the timing chain replaced.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Without any data, how can you make a conclusion that "400 miles per tank is not bad at all"???????

Brian- while that is certainly achievable, get a dose of reality and look at the EPA specs for 1985 Diesel cars:

Manufacturer Specifications for a 1985 Mercedes 300D | eHow.com

19 city, 23 highway, 20 overall. The EPA sites verify this as well.

We must keep in mind that the OP's car is a 1985, as those seem to be more dismal than 1983:
1983 Mercedes-Benz 300D Fuel Economy Ratings

The window sticker specs seem wildly optimistic- as has been with every car I've ever owned.

When we owned the OP's wagon, we got a consistent 25- 27 MPG, but I kept it tuned including a new timing chain every 100K. Most people think that a timing chain and tensioner every 100K is overkill, and the maintenance guides don't mention it, (380 engines aside)but I've seen enough carnage in the 120- 160K range over all MB models to make me believe that it's cheap insurance.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.