What should be the normal ALDA adjustment screw range? Mine only goes a total of 360 degrees before I encounter stiff resistance in either direction. And if my range does seem limited, what can I do to fix it? My 82 300d exhibits very slow starts in 1st gear up to around 2000 RPM and gas mileage of around 22 MPG (city) and 24 MPG (highway). I know others have said that you do not want to forcefully adjust these things...

Look elsewhere. Low power and low fuel economy do not point to the alda as a problem source. With a bad alda you'll have either really good power and low mpg or low power and really good mpg.

Check the valve adjustment, turbo boost and overboost valve

Problems are not always "single source."

thats what I said.

What you said was that the ALDA could be excluded from consideration because it could not be singlehandedly responsible for all of the reported symptoms.

right. the symptoms he discribes do not point to the alda as a problem.

1- his adjustment 360 in both ways made no difference.
2- he hasnt done anything else (that hes told us about)
3- he has low power AND low mpg, an alda wouldn't cause both.
4- a broken alda would have no power all over the range instead of just under 2000

Cites facts not in evidence.

However, adjusting the ALDA through its entire range without effect is definitely indicative of an ALDA problem.

Maybe one problem is ALDA related and the other has a different cause.

An improperly adjusted/malfunctioning ALDA can have a very significant effect on low-end power.

Wrong.


"Maybe one problem is ALDA related and the other has a different cause." disproven, see the previous post.

however it was proven not to be a factor in his case.

The best proven position for the ALDA screw adjustment is to leave it on your bench along with the rest of the ALDA.

The MPG problem this can create is solved with a really stiff spring under the pedal of your right foot, or train your foot.

In all seriousness, if you even suspect ALDA is a contributor, pop it off the car and go for a drive. If it turns out to be the problem and you want to put it back on the car, work the problem backwards until you find the reason. Or not.

__________________
Cheers!
Scott McPhee

1987 300D

Where is the proof?

I would submit that the only thing "proven" thus far is that creative reading is alive and well.

I can't tell how far is too far, but I did turn mine ccw, IIRC, it was a bit stiff the further I went. But it's still there and I have a car now that will get out of it's own way and the expected mileage drop has occurred.
Some folks remove it completely.

__________________
83 SD

84 CD

read. if you actually understood how the alda works and what it effects you would already know.

whats with your absolute fixation with making the alda become the problem?

If you've hit 'stiff resistance' there is a good chance you might have damaged the solder joints in it.

What regular maintenance have you done?
-fuel filter change
-valve adjustment
-injection timing adjustment
-timing chain check and/or replacement

The ALDA should be the last thing you adjust.

__________________
1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

Thank you for all the replies! Upon realizing the limited range of the adjustment, i set it back to its original position, which was fully ccw. It is my understanding that ccw enrichens the mixture and would result in better power/lower mpg. so if i move it cw, i should get worse power and better mpg. for the hell of it, i will try moving it cw and see.

the valves are properly adjusted, both filters are good, but i have not checked IP timing or timing chain stretch. the turbo is putting out pressure to the alda through the overpressure switch, but i have not measured the quantity of boost for lack of a gauge. Other than a slight engine miss at idle when the engine is hot, my only issues with the engine are lack of power below 2000 rpm and only getting 22 mpg city, 24 mpg highway (around 70 mph)... and as far as driving habits, i am not a leadfoot. i grew out of that by my mid 20's

I have only owned it for 3 years and have no idea of the prior history, other than the alda cap seal was, predictably, missing.

but the original question, what should be the normal range of motion in the alda adjustment, still stands...

IMHO if you want to keep your ALDA, you're much better off playing with shims under the ALDA than trying to adjust its screw. It's a hermetically sealed device, or should be. Breaking a seal that allows atmospheric pressure in(out,whatever) to seep is badness for ALDA.

__________________
Cheers!
Scott McPhee

1987 300D