I'll 3rd the call to dump the K&N filter, Frank has nailed it. The car had a cold air intake from the factory, which provided more than adequate air. Sucking hot air from inside the engine bay may actually decrease your performance. A very simple test to prove/disprove: time a few 0-60 runs with your K&N filter in place, average the numbers. Restore the factory filter, and repeat the test. I'll bet you a donut that there will be no meaningful difference in the numbers.

You can temporarily install a pressure gauge to measure the turbo boost, which should be around 12 psi, to see if your power issue is related to boost.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Here is your pic, rotated 180 degrees, ALDA circled in green and the cover circled in red. Under that cover is a lock nut and a slotted shaft. Loosening the lock nut and turning the slotted shaft while the intake manifold is still in place is difficult, but not impossible.

Under wide open throttle acceleration, if all else is correct on the engine (i.e. timing chain is 4 degrees or less elongated, injection pump and injectors in spec, no excessive carbon build-up in the pre-chambers, etc. etc.) then you should just be able to see some wisps of smoke in the rear view mirror, during daylight. With time the ALDA will age to the lean side, so your injection pump won't inject enough fuel to take advantage of the extra air that the turbo is supplying. Turning the slotted screw out 1/4 or 1/2 turn may be enough, some need more. Some people prefer to shim the ALDA instead of adjusting it, as there is a slight risk that the ALDA is at the end of its travel and further adjustment can break it.

Attached Thumbnails

 

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Awesome guys, thank you!

I installed the K&N Flat filter inside the factory air box, my old V-8s ran pretty well with them too, I instantly noticed the air horn pulling air from the grill. ;-)

OK, I did a LOT of detective work and found a LOT of BS going on under the hood!

EGR is blocked with a BB in the line and a plate under the EGR body. I read that the European models didn't even have an EGR. Why is this?

Turbo not kicking in was due to a 5/16" line from the wastegate actuator to a port on the side of the intake manifold. I read a VERY informative article on replacing the wastegate actuator and learned tons. In the article, the poster put a port on the horn of the Turbo, almost like in the pictures from Mercedes, showing exhaust parts. Anyway, I replaced the line with a 3/16" hose and now I get an OK turbo reaction, still not anything like I remember from my father's old Ford 4cyl. His turbo came on off idle and "boosted" it up and died off, like a turbo should; whereas mine comes on around 2000 rpm and dies about 3500 or so, sometimes much sooner. Hmmm...

Thank you Maxbumpo, I am still scared to get into the ALDA, since I have not seen great diagrams/pictures on how it all works and goes together. I DID find that some asshat put a screw down in the pressure line to the switchover valve and the other end was disconnected from the ALDA! UGH!!! I replaced all the vac lines through there and it has much more get-up and go now, but still bewilders me about the turbo... I am thinking that whoever "replaced" the turbo, may have installed the wrong one, or one with the wrong actuator?

I replaced the o-rings on my injector pump, which went pretty well! :-)

QUESTION:

There is a vacuum switch of some sort on the side of my intake manifold, it may be in one of my pics; there is a vacuum line from the big feed line to the brake booster, which gets oil in it, that plugs into (I think #3), a line comes out at 90º from that and goes to the shut-off valve? (Gold top hat in picture). I think that is marked as #2. Then at position #1, which faces the firewall, there is a piece of vacuum line that is about 3" long and just hangs there. Any idea what this is? Where I can read more about it? It has about 3 electrical connectors on it.

Can I just connect my intake manifold port, to the switchover valve, to the ALDA? Or will this give too much pressure?

Is there anything else I should look for, to correct? I took the intake tube off and it was pretty clean, as was the inside of the intake, so the EGR has been disconnected for a while and I am not worried about getting it put back on or working. Is this messing with anything? Is there a way to trick the computer into thinking that it is still attached?

Someone mentioned checking the EDS with a test light, for codes, yet I haven't been successful finding a "how-to" on it, anyone have any leads?

I really do appreciate all your help everyone... Thank You!!!

My '93 is all plumbed correctly it appears, if you need pictures I can send them to you. I do not know if the wastegate is pressure or vacuum operated, just getting into this, sounds like it is computer controlled via vacuum, ... if so I will be finding a pressure-wastegate and swapping mine out so that the computer is out of the mix.

As far as the EGR, up to you IMO. There is little effect from the EGR in performance, if any, and I suspect little change in NOX emissions also. If a pressure (direct acting) wastegate like the 603.960/.961/.971 had is fitted it will no longer rely on the computer signal for boost actuation.

__________________

Gone to the dark side

- Jeff

Yes sir, I would love to see pictures of the crossover valve on the side of the intake manifold, as I have the one line just hanging in space, I doubt it is supposed to.

I am guessing that the wastegate is pressure activated, my issue is getting it to pressure up consistently. This thread helped me tremendously: Wastegate actuator swap for OM602.962? understand a lot of the parts and their mechanics. I am also reading an awesome article on VW TDIs that relates to a lot of diesel turbos.

I just want to get it up and running reliably and consistently, which I am getting closer, as I can feel a power increase already. Supposedly, according to the diagram on the hood, the wastegate actuator is run by a hose from in front of the aircleaner. Mine had a screw in it, and the ill fitting tube from a fitting on the d/s of the intake. I am guessing that it is too far away to give a good pressure to the actuator. Time, I think, to remove the turbo and put a pressure fitting on the horn. I would love to ultimately bypass all the computer controlled stuff.

What is the L7 on the Injector Pump? It has an electrical fitting on top, I am wondering if this is controlling internals, holding the IP back.

__________________
Doug F.
92 W140 300SD
South Florida


MBCA member
Road Star Chapter

My pic upload failed, probably too large. Send me an email and I'll attach it to the response.

The device next to the ALDA with the electrical fitting is IIRC idle control.

__________________

Gone to the dark side

- Jeff