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  #1  
Old 09-04-2013, 11:31 AM
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ALDA adjustment was necessary. zoom!! but why?

i thought my trouble getting up hills was down to the trio of 2.88 diff, manual transmission, and large tires, but an ALDA adjustment may have just made all the difference. the engine now sounds heartier and the car comes off the line a good deal more quickly. i left the screw at 1.5 turns CCW but i think 1 turn might have sufficed.

my question is this: what changed over time to necessitate this supposedly unnecessary adjustment? have the aneroid devices in the ALDA itself sagged out of shape? are my injectors dirty enough to have been impeding fuel delivery? what else could have happened in the engine's first 110,000 miles of service that would necessitate tampering beyond the tamperproof cap?

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  #2  
Old 09-04-2013, 12:03 PM
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Quote:
Originally Posted by bricktron View Post
i thought my trouble getting up hills was down to the trio of 2.88 diff, manual transmission, and large tires, but an ALDA adjustment may have just made all the difference. the engine now sounds heartier and the car comes off the line a good deal more quickly. i left the screw at 1.5 turns CCW but i think 1 turn might have sufficed.

my question is this: what changed over time to necessitate this supposedly unnecessary adjustment? have the aneroid devices in the ALDA itself sagged out of shape? are my injectors dirty enough to have been impeding fuel delivery? what else could have happened in the engine's first 110,000 miles of service that would necessitate tampering beyond the tamperproof cap?
The Metal Capsules/Diaphragms do get stiffer as they get older and can ever crack.

If you have an ALDA that means you have a Turbo. It also could be your Turbo or the Boost Pressure to the ALDA is falling off.

The Fuel Injection Pump is adjusted on a Test Stand and there is an acceptable upper and lower range of Fuel Delivery. You Pump could have come off the Stand set at the lower Range.
Also the Test Stand measurements are all mechanical. There is no Engine to respond to the adjustments.
I have seen on other Turbo Engines where the adjustment on similar Devices needed to be tweaked after the Fuel Injection Pump was on a running Engine.

The last issue is that IPs may be tuned to give a specific Emissions out put; not to make the Car Fast.
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Old 09-04-2013, 12:06 PM
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There is a piece of metal inside that flexes every time you accelerate, fails or gets filled with soot. If you think this is good, try no ALDA + boost gauge.
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Old 09-04-2013, 02:06 PM
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Another forum I was some years ago on had a former Mercedes tech, Stu Ritter, who worked for a big dealer when these cars were being sold new.

In addition to all the other factors the other two respondents mentioned, Stu said that many cars were delivered with the ALDA and turbo way under spec, so that in some cases the later adjustments weren't really enhancements, they were just bringing the car up to spec.

In some cases they were so bad that dealers adjusted them prior to delivery (dealers had access to replacement tamperproof caps).

I was told by the lady I got my '85 300d from, that after she inherited my car from its original elderly owner, with only 80k miles, her husband did some online reading and ended up taking it to the dealer not once but twice to have it set up properly.

According to her this was just to get the car into spec... and let me tell you, my car gets up and GOES....
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Old 09-04-2013, 02:16 PM
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you might check your boost I drove around with 9 psi for a year,and I was only getting 1/3 throttle.Fixed pedal,and ran boost up to 15 psi,man different car.
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Old 09-04-2013, 03:13 PM
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this is an '85 california engine that did come with the extra emissions equipment (ARV, EGR, rack position thing, trap ox, not sure what else). sounds like it may just have been configured to run lean from the factory. it makes me laugh to think of all those posts i read saying "adjusting the ALDA won't increase your power". i guess others don't necessarily have this problem!

i have a boost gauge; pressure currently tops out around 8.5psi, down from 9psi with my previous turbocharger. i have a manual boost controller too, but i've been hesitant to install it without getting a pyrometer first.

thanks everyone for the input!
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Old 09-04-2013, 04:37 PM
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Adjusting your Alda wont give "more" performance. It will give you your performance back. Those are two very different things.

I suppose that's vague, but what people mean when they say Alda adjustments don't increase power, Alda tweaks won't take you from 125hp to 150hp. But they will take you from 100hp and sluggish starts back to 125hp and "like new" performance.

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