Subject: Mercedes 300D turbo, 1984, 40mph tops, diagnosis?


I will do my best here. Please ask if I have been vague anywhere. Feedback welcome, desperate. Will attempt fast reply. Chilton's manual coming in mail,
will be working on car end of the week.

Car has gradually lost power over 2 ys time, used to reach 80mph, now only 40 on a hot day. Had a compression test 8 ys ago, (400, 380, 380, 340, 340, , 280). What can I draw from this data? Looks bad to me. Car starts great, engine sounds fairly good, revs good, 3.5k rpms when not in gear except: surges some times when in gear when maxed out, missing some I think, won't get over 20mph on cold morning for at least 20 minutes, dead on hills. Does NOT smoke! Engines sounds pretty good when it has no load on it, but hills, load etc and it is a slug.

I have 2 injectors off, all hoses off, modified 27mm wrenches to fit. Seems quite rusty in both injectors, discolored redish with flakes of material floating about. Metal jets look clean enough.
Blowby test seems strong. Someone suggestion strongly that it was a vacuum leak?

Main issue - Seems vastly underpowered, though accelerates up to 20 fairly well, but when cold, will not go above 20.

Should I go forward with, ( AND in what order?) replace fuel filter (s), (air filter seems good), injectors, Fuel pump (cringe, $400 to test if I remove, $900 to rebuild).

My stance - Had car 2 years as project, now may sell. Previous owner had minimal records of work. paid $1900, love these models to drive, had two now but student loans require I be shrewd, not romantic with cars at this point. I will unload it if it means high inputs over $1500. New injectors $150 each x7=$750. will be working on car end of the week.

Thank you sincerely for any help.

- Lev

ph# 7072289554

- "No car is as expensive as a cheap Mercedes"