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)

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