PeachParts Mercedes-Benz Forum - View Single Post

Jeremy5848 · #**351** 08-10-2007, 10:35 PM

Here it is, folks:

1987 300D Turbo (W124)
Odometer 136,000 miles (probably more)
Biodiesel B100
Altitude ~200 feet
Trap ox recall performed about 1000 miles ago, turbo replaced too
Clean air and fuel filters
Speedo low by ~3% (57 MPH speedo = 60 MPH GPS)
Odometer low depending on how much it spends doing nothing -- this time 24%
Fuel economy using GPS as tripmeter: 20 MPG (279 miles, 14.0 gallons, B100)

With gentle footfeed, the car starts off from a dead stop feeling like it really wants to go but the promise is not kept and the acceleration eases off after the first few seconds. Full immediate footfeed gives "slug" performance. The same feeling of "nothing" occurs when the accelerator is floored with the car running at 60 MPH. Acceleration is almost non-existent; one must make an appointment long in advance to overtake another vehicle.

0-60 time (analog stopwatch, 1970s vintage)
Test 1 (gentle footfeed at first) 21.5 seconds
Test 2 (full footfeed immediately) 27.8 seconds
Test 3 (full footfeed immediately) 26.0 seconds

By comparison, the W123 car (1985 300D Turbo, California version with trap catalyst, EGR removed, ARV disabled, B100 biodiesel, 225000 miles)

Test 1 (full footfeed immediately) 19 seconds
Test 2 (full footfeed immediately) 19 seconds

The '85 accelerates well from 60 MPH, by the way. I'm sure it will do even better once I get the trap cat replaced with a 'test pipe.'

Incidentally, neither car has had its accelerator linkage checked so I'll do that next as well as look at the 87's airflow sensor to be sure it isn't stuck partway closed. I also have a few more pieces of vacuum hose to replace on the '87.

Jeremy