I don't really know how best to title this post but if you are reading it, the one I used worked!

Anyway, since I have never driven another MB w123 with a turbo I can't compare it so if you guys can give me some insight, I'd really appreciate it...

After the engine is at operating temp and from a dead stop it is a little sluggish but NOTHING like it was when I first got it in August! (Had the boost line and banjo bolt cleaned out!) It runs sooo much better that I am only assuming that it probably doesn't get much better so I am fairly well satisfied with it's performance "off the line". What I'm concerned about is the predictable BLAST in acceleration at exactly 2500 RPM! Don't get me wrong, I like the feeling of the power it has BUT I don't like it EVERY time I leave a traffic light. Am I making sense? This behavior may be perfectly normal but as I stated, I can't compare it to any others! Help...

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Dale

Well to kinda explain it as clear as mud....... As the engine revs up, the turbo builds boost pressure in the intake manafold which has a small line attached to it which goes to the ALDA on the injection pump. As the ALDA gets boost, It inturn gives the injectors more fuel which inturn creates more exhaust pressure which turns the turbo faster which inturn creates more intake manafold pressure............get the idea??? You are feeling the engine get into its "SWEET SPOT". You can help things along by turning the sealed screw on the alda a 1/2 to 1 turn counterclockwise. This gives you more fuel at zero to low boost. The car will pull out better and thus you will have to throttle it less to get going...... Clear as mud!!!

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My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.

Since this is a sealed screw, was it never intended to be 'fiddled' with?! I mean, surely this car didn't act like this the day it was driven away from the dealership so what has happened over the years and miles? Just the wear-and-tear factor? Did MB anticipate at some point in the life of these engines, they would need to unseal this sealed screw and tweak it?

Thanks for the reply, Motorhead

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Dale

The dealer tweaked the screw on my 123 for the PO as part of a service call.
-nB

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'83 300D Turbo
Current: ???K mi - 19.2mpg -> 17.4mpg -> 22.9mpg ---> ODO Died
bought at: 233.8K mi - 10MPG For $1.00
3.5 cylinders work: 320 320 100 340 280
Got insurance? FarmersReallySucks.Com

Never assume anything?

You need to do an evaluation of the fuel supply, vacuum, turbo, including all electro switches.

If you are getting boost, and it sounds like you are, the rest of the issues are likely less expensive to deal with.....turbo chargers are expensive etc........

The archives here may reveal more info...............

You have an 85. All 85's have an ARV on the turbo. The ARV is an emissions device used on these cars to increase the amount of EGR. This limits boost until about 3000 RPM.

Do a search on ARV in this forum to figure out how to deal with it.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

Thanks Guys! Keep the cards and letters comin'!

You're keeping me busy on the search feature..

I DO appreciate the help.

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Dale

I agree with tweaking the ALDA, because with it untouched, the power will be exactly as 85 DSEL stated, it just surges as it hits 2000+ rpm (mine does at 2000+).

With the ALDA tweaked, you get more fuel off the line and won't feel the surge as much.

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http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

And I don't agree with tweaking the ALDA.....unless/until you have the car for a little while and are used to it's performance. And, do a Diesel Purge. And, set the valve lash (check timing chain while you are setting valves). And, change all fluids (unless you have some Maintenance records). And, assure that you have a clean air filter. And, check/clean out the boost pressure line that sends a signal to the ALDA......then, if you still wanna do some tweaking......go for it, just don't jump into tweakin' until you have a base reference point...

otherwise...have fun....and enjoy the surge....

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

it sounds like the car is running as designed.

use less throttle.

or just adjust..................your attitude.

(smile)

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Really?
I can't imagine a MB customer (whether returning or first-time) going for a test drive back in 1985 actually enjoying this and be ready to spend "big bucks" on a daily driver with an "attitude" this car happens to have now! Again, don't misunderstand what I am saying, I DO enjoy the power the cars has - I would like it even better if it were spread out over the driving experience a little more rather than a BLAST at exactly 2500 rpm! I believe I have "learned" how to work the go pedal since I took ownership so I can't make the desired adjustments just through a simple driving habit.

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Dale

Check your fuel timing lately? Probably not getting enough fuel in the bottom part of the powerband.

Mine does this as well, sometime's it's a pretty sudden rush that really pushes you back in your seat. This is with ALDA all the way out. I noticed it increased after increasing boost levels.

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1985 CA 300D Turbo , 213K mi

adjust the ALDA. Springs DO wear out!!
No, it didn't drive like that in '85.
adjust the ALDA.

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'82 Euro MB 300 D Turbo Silver/Blue - Fixed
Adding W115 Intake and Intercooler

1986 Chevy Camaro Cp 400HP For Sale
Engineer
Tuscaloosa, AL

I believe this is the first post I've seen of a complaint of too much power on these cars.

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Sam

84 300SD 350K+ miles ( Blue Belle )

SD Blue I'm surprised it has taken so long for your post (or one like it) to appear! AGAIN...I am not complaining about "...too much power...", just the sudden BLAST of it!

I have not done any of the diagnostics that have been mentioned here but am compiling information for when I am able to. Since I am still learning about this great car, I will be doing some adjusting of the ALDA as soon as there is a few free hours in my schedule! AND, I WILL report my progress to all you fine peoples.

Thank mucho!

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Dale