surfblau, what an intersting chapter in the life of your 300TD.
(You want to sell me the old parts that were good after all... ?)

Say I just saw Gus yesterday too! He is a rare resource isn't he?

Wanna hear my story? I had the IP for my TD (well, one of them) rebuilt by Gus last year. He did an asolutely beautiful job, complete with a computer print out of the performance, idle to test RPM, in multi-color bar graph form. Plus I got to see him doing his magic on a pump calibration station!

After installing the IP I always thought it was running rough, it had a slight loping when the engine was hot (OK cold) and a high idle speed too.
I wasted a can of Lubro Moly injector cleaner, finally changed injectors, installed another rack dampener pin (warranty by Gus), and a few other things I have intentionally erased from my mind.

The mechanic who installed it had said he couldn't adjust the idle speed down below about 920 RPM, which didn't really matter much until I had him install a new rebuilt transmission (due to a sudden surprise when the existing one locked up in low gear - another story!!) Now, the new tranny came up with a new torque converter which has a higher lock rate and caused the car to creep or maybe I should say, accelerate rather violently when the brake was released in gear. Clearly 900+ RPM was no longer acceptable, back we go to the drawing board.
Just as the mechanic said, adjusting the idle speed control made no change. So I go to see Gus for a quick consultation. In under ten minutes he showed me the workings of the IP and suggested that first the linkage between the IP and the rest of the throttle rack be disconnected to see if the idle speed or roughness was affected.
He also informed that if the rack damper pin was adjusted "in" too far, the idle speed would be excessive.

Voila! First the linkage to the IP was removed, and it was noted to be a little too long, causing the throttle to be pressing towards shut off (this is the same as pressing the manual shut-off button) and the damper was turned out slightly. Clearly a lash-up snafu.
Now the engine idles properly and smoothly and the mechanic gets an "F" grade.
Maybe we have passed each other on the freeway and didn't know it!
Dieseldiehard
'71 220 (gas) 4-speed manual "present project car"
'79 300TD w/ '85 turbodiesel engine
'83 300D
'85 300TD