My Alda doesn't hold vacuum, what do I do ? W123
 

Hi guys,

I am trying to fix my 1985 300D W123 and make it more drivable.
I did adjusted the valves, Diesel purge, banjo bolt clean, air filter, fuel filter... The basic on good tune up.

Car is better than when I got it, but It is still very sluggish specially below 2000RPM. I start boosting at 2000 RPM and will boost 8-9 psi max boost.

I am still learning on those engine and found out about the Alda.
Mine doesn't hold Vaccum. I guess it's shot.

Will removing it make my car faster ? what exactly to I have to do.
I would like to disable the EGR also.
I don't mind adding a manual boost controller and running a boost gauge to make sure I doesn't over boost.

As it is now, It's not a fun car to drive. I know it will never be as fast my TDI but Do I really have to slow down the traffic when I drive a 300D ?

I also have intermittent leak on my prime pump. Anybody as a part number so I can order one from the dealer.

One more thing when my car shift, sometimes not always I hear from the transmission a whistling sound. I know it runs on vaccum but should I hear it working ?

Thanks guys.

Benz
http://i22.photobucket.com/albums/b3..._r_us/benz.jpg

Go to Super turbo diesel board and have a look at some of the stickies at the top of engine section. Sounds like yours has the usual out of tune characteristics, some simple adjustments will really wake it up. You definitly do not have to slow down the traffic with that car.

make sure throttle linkage is opening all the way, I have had good luck tuurning the stop in a couple of turns (some say do not do this but it worked for me on a few cars) The Alda may be your biggest issue though, find out why it is leaking, then turn the screw out for more low end power. Also get a MBC and monitor boost with gauge. make sure T chain stretch with in spec.

Check STD board for more info, the key to power is in timing and a few simple pump adjustments. You need to make sure you have good nozzles and proper engine tune first.

Right,
Some guys have removed the ALDA all together. I dont reccomend this for anything but for all out drag racing. The ALDA is our friend in the street though as drivability and EGT (exhaust gas temperature) gets really important.
Find one and get tuning. There are some fast 617/602 guys in this forum

Cheers, Mike

I don`t think it is fixable, I`ll be up with my truck and trailer and haul it out of there to releave you of any stress and trama. :D

Charlie

Since the ALDA is only designed to hold pressure, and not very well at that, the application of vacuum to this unit will destroy it.

So, I believe your conclusion is valid.

I have the ALDA disabled on the SD, no problems.

How do you mean "slowing down the traffic"? What kind of speeds are we talking about? Does your car not pick up quickly if an when you stomp it?

I drive one just like yours daily. It slows down the traffic a lot, but that's more because of the way I prefer to drive and save fuel. Besides, that's what they have passing lanes for. However, every once in a while, some guy wants me to move over to the emergency lane and decides to park himself right on my tail. I've found that I can outrun most of these guys...after the obligatory cloud of black smoke that is. :D

So...its not that these cars don't "go", just whether you choose to make 'em "go" or not. :D

the ALDA is a sealed can like a barometer. Where you thnk you have a leak could be the vent to the atmosphere and won't hold vaccum. All this ALDA does is compensate for the alttitude and barometeric pressure. Adjusting the screw on top will allow the fuel rail to go in further so you get more fuel. The more fuel, the more power and the more smoke when you floor it. Your injectors may be dirty or gummed up. If they don't "pop" at the right time but leak you will have no power. or the pump may have scored clylinders and not pumping enough pressure.

From the FSM.