What idle valve line? These Diesels don't have any air throttle. The line from the manifold goes through a switchover valve then to the ALDA. It splits before the ALDA to provide a signal to the transmission vacuum amplifier (BFS). Which line is clogged?

Here, I found a diagram - http://www.peachparts.com/shopforum/2006956-post69.html

Here's one suitable for framing - http://www.peachparts.com/shopforum/2230146-post83.html

Sixto
87 300D

I mean the line that comes off the "y" on the Alda, to the idle adjustment knob deal on the shock tower! Sorry i dont know how to explain stuff very well

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06' 500R Ninja Naked/Café/Custom
86' 300 SDL (Donor)
98' Discovery 50th anniversary (Recipient of transplant)

Idle adjustment in this engine is mechanical (base idle) and electronic (ELR actuator). There's no vacuum or pressure control of idle. There is no pneumatic line to the idle trim selector, only wires. Per the diagram, the branch close to the ALDA goes to the 50*C switchover valve (Y29). Below 50*C coolant temperature (single pole sensor by the thermostat), the boost signal is blocked from the transmission vacuum transducer (123) also called blue flying saucer (BFS). If the engine was cold when you blew, it should have been blocked. When the engine is warm, you should be able to blow through to the BFS. I don't know if you can blow through the BFS or if it blocks further blowing. This line has nothing to do with idle or engine performance, short of a wholesale leak that subverts the signal to the ALDA. You might add another branch just upstream of the ALDA to plumb a boost gauge to the cabin. You should see about 5 psi at 2200 rpm under load and a max of 12-13 psi.

Removing the ALDA should allow as much fuel as the IP can provide under max boost even when boost isn't available hence smoke. If performance is insufficient with the ALDA removed:

- there's a problem with fuel supply or inside the IP
- the turbo is tired or there's a serious leak in the manifold
- you need to turn up the full load setting; probably should install an EGT gauge first
- put this engine in the SDL - http://cgi.ebay.com/ebaymotors/261281967606

Sixto
87 300D

Hello Mario,
Would you happen to have detailed instructions for what you did with the EGR, ALDA and solenoid to your 87 SDL. I have an 87SDL and a 92 300D Turbo that I want to pep up.
Thanks.

If it's anything like the 87 300d, unplugging the egr is pretty strait forward. You just unplug it and cap the line. There is another one below it. Infact, mine has a line going from the bottom valve (Recirculating air valve) to the top (EGR)



I personally see no reason to remove or unplug the ALDA except for testing.

Only the 1987 models are set up like this. The 1992 300D is completely different, and requires converting to a pressure-operated wastegate, there is a very long, very detailed thread about this.



Disabling EGR will not "pep up" your car. If you are having performance problems, EGR is most likely NOT the root cause. Disabling EGR will keep the nasty soot buildup out of the intake manifold, and may increase fuel economy slightly, but it will not increase power.

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Removing the EGR valve made a huge difference on my car. The valve didn't seal up completely when closed because of all the grime on it. I could blow air right through. Disable it if its still functional and remove it completely if it fails to make a perfect seal.

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Exactly. Disabling a bad EGR valve won't improve performance. The problem was the valve not sealing. The fix is to clean the valve, that would improve the performance (or, remove it entirely, which is more difficult on the 90-up engines).

I modified an OM603 ALDA so its easily adjustable by hand without any tools. I've been running without an ALDA for about a year now and I'm quite happy with it. It only smokes if I'm flooring it and it hasn't hurt fuel economy at all but I wanted other people to be able to drive the car without having to think about it. I removed the cover, lock nut and washer at the bottom, pressed a small length of 5/16" OD polyurethane tubing over the top part of the screw followed by 5/16" ID rubber hose over that. In the picture its adjusted all the way out.

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Is this one of your infamous UROparts upgrades?

You seem unhappy with your life.

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I'm sorry to hear that. These people might be able to help you.

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Thanks for posting this. My OM603 smokes too much at idle when cold with the alda adjusted (with washers) all the way out. The smoke is due to too much fuel being unburned. But once the engine is warm, it idles clean.

I have been trying to find a way to make the ALDA user adjustable from inside the car, so your post has given me a few ideas. That way, I could keep the ALDA adjusted for less fuel when I first start the car in the morning (to keep from polluting around my family too much), and then once warm, I could adjust the ALDA to provide a bit more acceleration.

Has anyone done this?

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1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).

This might be a bit too complicated for a simple cold start issue but gives you an idea of whats involved.
http://i172.photobucket.com/albums/w20/stamsaas/Ke70/20130112_162231.jpg

Dieselmeken shows outside adjustable ALDA for Mercedes Superpumps - YouTube
An easier solution might be setting up your glow plug system for afterglow.

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There is no need for this. When the ALDA is adjusted correctly, you should not need to touch it again for a very, very long time (if ever). Smoking at a cold start in winter is pretty normal. An afterglow conversion would help for the first 60-180 seconds after a cold start, depending on which relay you used.