'87 300TD poor performance returns

[msyoder]

Hey Folks,

Haven't been very active for some time. In some ways that's a good thing (nothing realy bad has happend to the car in a while), but it's nice to read the familiar names in the posts and see the 603 engine community growing. Dave (gsxr), sorry about the hole in your engine.

Lately (over the last year) my performance has grown worse so I revisted the standard things: preasure lines and SOV to the ADLA are clean, changed the fuel and air filters. Finally I measured the boost and got only 5.5psi max at 4400rpms under full load acceleration. The manual indicates that this should be 11-12psi.

The boost preasure has been measured on my car at spec since the the trap oxidizer was replaced in 2000. Then my 0-50 times were 10sec. Now I'm lucky to get to that speed in 14-15 sec.

After a couple of enjoyable hours of reviewing the ADLA and power topics I understand that there is a feed back loop between the fuel enrichment and boost.

I'm getting the sense that my ADLA may be getting tired. And I should test a small adjustment and see what affect that has. I was just going to ask how one accomplishes the ADLA adjustment on the om603 with the manifold in the way when I ran across a link to Dave's excellent photos on the topic.

http://www.meimann.com/images/mercedes/OM603_injection/

I like the idea of the washer/shim to preserve the sealed adjustment screw. Does anyone think there is a downside to that over breaking the seal? What might the ratio of shim thickness to turns of the screw likely be?

Anyway, now I'm psyc'ed to get my baby back in the fast lane.

Thanks,