Hi everyone.

I am new to MB. I am hours away from purchasing a 1980 300D. It is in great condition interior and exterior, cept for slight paint oxidation.
Anyways, the reason I'm writing is that I can't get over the lack of acceleration.
I've searched through the posts here and my problem sounds a little different.

Engine runs smooth, no knocking, slight smoke at start up.
Automatic Transmission shifts very smooth (course, I'm used to a stick shift).

Acceleration - from a dead stop, an Ant can outrun this vehicle, in fact I think I could run faster in waist-high water than this vehicle start (no joke!).
Once it shifts to second, the acceleration is pretty good. The tachometer is broke so I can't tell RPMs where good acceleration kicks in.

This doesn't seem normal, It actually seems kinda dangerous.
In fact during the test drive, I had people honking at me cuz I didn't want to make a left hand turn if there was any oncoming vehicles within a 1/2 mile.

Anyone know what might be causing this?

Thanks in advance.

There are a number of possibilities. Does this car have a turbo?

The first things that come to my mind are the banjo bolt and the rack dampener pin. Actually I don't think the pin is a common cause of slow acceleration from stop, but it made a huge difference on my car when I adjusted it.

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

No offense, but the above won't apply as your car is a non-turbo.
Is it shifting way early, espcially from 1st to second?
BTW, that car will never be a rocket, but it shouldn't be dangerous.
Do a search on valve adjustment. Always needs adjusted/checked with a "new to you" MB of this chassis. Then you might move on to IP timing, but that starts to get more complicated in a hurry.
Have you replaced your two fuel filters yet? Also check the tank screen, as noted below.

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Sounds like fuel starvation. Replace the two fuel filters (the spin-on and the pre-filter). Also, the fuel tank has a screen filter in the bottom that may be clogged. Run the fuel down low and pull the screen to inspect and clean.

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2008 Jeep Grand Cherokee 3.0 CRD (OM642)

1984 300d Turbo 139k
Do A Fuel Injector Purge From Dieselgiant.com Get Two Cans Of Dielel Purge Go Into The Fuel Injector Fuel Pump At The Small Hand Pump Rt Side, From The Large Fuel Filter To Return Line To The Can Of Diesel Purge, Run Engine 10 Min

Thanks for the quick responses.
I'm not hearing anything that sounds like it could be to serious, yet.
Like I said, I haven't bought the car yet, just wanted to see what possibly be wrong before I did.
I still plan on buying it based on the responses here.

Thanks again.

I don't know how the 80 operates but a 77 300d starts out in 2nd gear unless the accelerator is pushed hard enough to activate the downshift or if it is manually put in 1st (it can then be returned to drive). They are real dogs starting in 2nd.
From your description, I suspect yours is also starting in 2nd. MB designed this feature into the 300d's so that people in 240d's wouldn't feel too bad when riding in a 300d.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Carbon fouled piston crowns and valve seats...... Often if these old diesels never see any highway runs and are constantly lugged at low rpm's the chambers will foul with carbon deposits causing incomplete fuel combustion.

I tried manually shifting to 1st, then 2nd. Didn't seem to change much.
I turned of the AC, minor improvement.

Do you see excessive brake dust on the rims? It may be possible the calipers are sticking.

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2008 Jeep Grand Cherokee 3.0 CRD (OM642)

Good one, I'll check it out.

I've always wondered about this. Tell me that's not the real reason for the 2nd gear start! Does anyone know what the logic MB had behind this?

With the AC on, the '79 300D is definitely doggy. I usually turn off the AC if I want better takeoff from a standstill- it helps a little.

Colin

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1979 300D 184k Km

A lot of people did/do this with their manual trans to get better fuel economy. In fact, I remember in the 80 & early 90s chrysler/mitsubishi vehicles had a power and economy setting on the auto trans. My sister had this in her 1990 Plymouth Laser (rebadged Mitsu eclipse) and all the economy mode did was start the car out in 2nd gear and the power mode would start it in 1st gear.

I am just assuming here, but I would say they did it for fuel economy. Plus, it isn't as hard on the Diesels since they have more torque than a gasoline motor.

IIRC from reading other posts, the 2nd gear start was discontinued after 1981. My 82 starts out in 1st.

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2008 Jeep Grand Cherokee 3.0 CRD (OM642)

the 80 didnt have a turbo IIRC they became turbo in 83 after the wagons did..

Partly correct.
Wagons got the turbo in '81
Sedans and coupes got the turbo in '82

My 80 wagon would start out in first, btw..... Only took about 10 seconds to build up enough speed to shift to second!

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John