The ALDA is the device on top of the injection pump. It's not connected to the intake. It's fuel restricting device that functions with boost as it's sole input.

Under the ALDA is "nut" that is machined into the base of the unit. Below this "nut" is an actual nut that lives on the top of the injection pump.

To remove the ALDA, you need two wrenches, a thin wrench to engage the "nut" on the bottom of the ALDA unit and another wrench to engage the actual nut just below it. You position the two wrenches so that the upper wrench is just slightly clockwise of the lower wrench. Then, squeeze the two wrenches together and the ALDA will break free of the lower nut. Now, just unthread the ALDA from the lower nut and plug the hose.

I think some of you "new" owners have way to much faith in what that ALDA can do for you. Forget it! That isn't the problem. You can sometimes reduce smoke, maybe pickup a slight bit of performance, but to change anything in a meaningful way, it won't be in the ALDA.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I should add that unless you really know what you are doing, never get within 3 feet of that injection pump with any wrench. More owners have screwed up there good running engines by wrenching on it then any other part. Just make a promise to yourself, that the pump is a "no touch" deal! You will find that the pump is now the problem with your engine.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

By disconnecting from the intake, I meant disconnecting the boost line that connects the intake to the ALDA... I disconnected the boost line from the ALDA and hooked it straight to my boost gauge, drove it around, and it was actually worse acceleration.

That's to be expected since the ALDA is no longer getting a boost pressure signal from the line.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Others can answer this question, if the stop lever is pulled full stroke will the injector pump lever go to high idle ( max RPM ) ?

The only way to check for full throttle is to have someone push the peddle in the cab then look at the high idle stop on the injector pump. If the lever does not hit the stop you don't have max throttle.

Is the engine easy to start? If so the pump timing isn't that far off.

Tall rear end gears will actually allow you to build boost early as the engine is pulling against something rather than free runnning.

With 33 inch tires you just may be loading the engine down so it cannot get into it's power band. I would do all the calculation in comparison to a normal tire and wheel of a 123 type with the same rear end ratio. Or even worse the engine just cannot produce the power you need under the current gearing.

If you have a say 2.0 final ratio I suspect the engine will not pull it well depending on vehicle weight. Mark the tire and turn it one complete turn while counting the driveshaft turns. Then divide or multiply by two to get the ratio. I am just not positive at the moment if it is multiply or divide.

The reason your boost reads low perhaps is just low revs on the engine. Once you have valid numbers They may indicate you do need a lower ratio rear end ratio. The acceleration is slow on your example. I do not see any numbers posted so far. Rpms at 60 for example would give at least a hint. Did you notice when the transmission gets into fourth? I think you would want to see at least 2500 rpms at 60 and that is only if the vehicle is lighter than the car it came out of.

I would forget the engine itself for right now and find the true rear drive atio.

I cut the cap off the alda, turned it a half turn ccw and drove it, not much difference. Turned it another half turn and drove it, could tell there was improvement. Turned it another 3/4 turn (would not turn anymore) and it drove much better. Not a sorts car off the line but that is to be expected with the larger tires. I gets up to 9psi boost before it shifts.

Btw, it fires right up the instant I engage the starter, no hesitation what so ever. My transmission is a 3 speed with 1.00 final drive. I am planning on swapping in 3.73 gears in my front and rear ass to improve highway performance.

What exact transmission do you have behind it? OE is a 4 spd.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

It is a tf999 3 speed auto. With 2.74 first gear, 1.54 second gear, and 1.00 third gear. I unfortunately do not have a tach yet, its a bit tricky getting a tach going.

Do you know the ratio of the present differential gears? Weight of vehicle etc. A tire diameter of about 24 inches on one of my mercedes Gives it a circumferance of about 75 inches. A 33 inch tire about 103 inches. If your vehicle is not too heavy 3.73 gears as you mention might do you.

1st gear is not low enough compared to OE.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Do you know what the trans gears were in the '85 w126 300sd? I looked last night and couldnt find anything.

from what i found, the 85 300sd had 2.88 gearing in the rear end and came stock with 25" tires. 25/2.88 = 8.68

Right now I have 3.07 gearing in the rear with 32" tires. 32/3.07 = 10.42

If I go to 3.73 gearing and keep my 32" tires, it would be:
32/3.73 = 8.58

So that would get me back really close to the right gearing. But that all depends on what that 85 300sd trans gears were for 1st, 2nd, and 3rd (Everything I found said they came with a 3 speed auto as well???)

I do think I am getting some restricted fuel flow though. I looked at the primary fuel filter this morning, and after about a total of 1 hour of the engine running, there looks to be rust flakes in there from the tank. Also, the fuel supply line looks to be 1/4" going back to the tank, everything i have read says it should be 5/16" for these motors. So I think I might end up dropping the tank, cleaning it out, and running new 5/16th line front to back...

85 SD had a 4 spd. All 617's had 4 spds. I looked on here last night and found the gear ratios with a search. By memory 1st was 3.68 or something like that.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

So I went out tonight and checked the timing via the drip method. Got 1 drip per second at 21.5 btdc. So my timing was definitely retarded. I set the crank at 25 btdc and rotated the ip until I got 1 drip per second. I turned the alda back to original position and started it up and it runs better but runs better. I think I still need to adjust the valves though. I can't check for black smoke at wot until tomorrow after work.