300D Accelleration - PeachParts Mercedes-Benz Forum

tobybul · #1 05-19-2006, 09:24 AM

Thought I'd post this question again.

You Fellas who have 300Ds, hows the take off accelleration on these cars? I am driving a friend's 1985 300D right now and I find the accelleration from 0 mph to be extremely anemic.

For a turbo, I thought it'd be a little bit more peppy. Once its cruising, it performs ok. Is this normal that it starts off very slow even with the pedal down to the floor?

Can something be done to the engine (turbo, etc) to improve take off? I already cleaned the Banjo bolt (which was not that dirty). Didn't make a difference.

Thanks

Rashakor · #2 05-19-2006, 09:34 AM

again.

-Italian tune up
-purge
-valve adjustment
-Alda

d.delano · #3 05-19-2006, 11:33 AM

Adjust linkage to make sure you're reaching full stop on the IP, grease linkage balljoints as this will make accelerator feel much better
If you don't adjust the valves don't bother trying anything else. It should be the first thing on your list. You could try checking to see if the injection pump timing is correct. Might want to hook up a pressure guage to see how much boost you are getting at WOT. Adjust turbo wastegate if below spec. Other than that that's all I can think of.

rhodes2010 · #4 05-19-2006, 11:41 AM

It is true that the way we end up driving these is accelerator to the floor,
when you eventually reach desired speed, back off throttle.

I tell people that my car does not accelerate - it accumulates speed.

What you are experiencing is probably normal, even in the very best of circumstances.
But as you noted, when you are up to speed, it runs very well.

The sensation I have driving my diesel 5 cylinders is much like driving a boat.
Open road with cruise or open throttle it is best.

Any gas powered car accelerates differently(better/faster/quicker) than the diesel.
I do not think your car is broken, it is just the quirk of diesels.

TheDon · #5 05-19-2006, 12:33 PM

Quote:

Originally Posted by rhodes2010

It is true that the way we end up driving these is accelerator to the floor,
when you eventually reach desired speed, back off throttle.

haha thats how i drive.

when you do the banjo bolts the washers both go on the side opposite the bolt head.. i mixed that up and had slooooow acceleration because the holes were covered

tobybul · #6 05-19-2006, 12:52 PM

Quote:

Originally Posted by Rashakor

again.

-Italian tune up
-purge
-valve adjustment
-Alda

I wasnt ignoring anyone's comment. I was just waiting for a bit more info and something a bit more "scientific" that I can put my hands on. Didn't quite understand the banjo bolt washer placement deal. Isn't it more on lining up the banjo hole to the bolt hole? Now that you brought it up, not sure if I did that or not.

The valve adjustment deal seems a bit more involved. I know Diesel Giant shows the procedure online. Since the car isn't mine - yet, I am trying to decide whether to buy it and put up with the work which may or may not "work".

TheDon · #7 05-19-2006, 01:32 PM

the banjo bolt is hollow and has holes underneath the head which has a ring and ALDA line attached to it.. the bolt it placed through the ring and bolted to the intake.. the pressure goes through those holes to the ALDA unit. if the holes are obstructed the ALDA cannot increase fuel ... the washer deal. it should probably be one on each side of the ring. but i havent had any adverese effects

d.delano · #8 05-19-2006, 03:02 PM

Quote:

Originally Posted by tobybul

I am trying to decide whether to buy it and put up with the work which may or may not "work".

how much rust?
that should be your concern, in Michigan

tobybul · #9 05-19-2006, 04:12 PM

Surprisingly the car does not have much considering its 30 yrs old. If I were to apply a percentage, maybe 5 percent if that. The underbody still has the original MB coating. Some rust on the Jack holes and some on paint chip by one side.

This is probably a testament to MB's method of rust proofing their cars. This car looks very solid and feels like a tank. The sheetmetal seems like its 2x the thickness of the newer ones.

The moonroof still works. All electrical still intact. I may change the sealed beam lights. They look a bit dull. But those fog lamps!! They're expensive!!

Wish I could just figure out how to give it some take off ummmppph!

Skippy · #10 05-19-2006, 11:36 PM

My 300 has had the banjo bolt cleaned (by me) fairly recently. It made a difference, but not a big one. I haven't adjusted the valves yet, or messed with the ALDA. The car is very slow from a stop, but once it hits about 1800-2000 rpm, it takes off and accelerates very well. With a high-rpm launch, my manual transmission 240D could probably beat it to 20 mph, but then the 240 needs second gear, and it would be all over after that.

Diesel Giant · #11 05-20-2006, 12:10 AM

Quote:

Originally Posted by Rashakor

again.

-Italian tune up
-purge
-valve adjustment
-Alda

Ditto.

#12 05-20-2006, 12:17 AM

Quote:

Originally Posted by tobybul

Surprisingly the car does not have much considering its 30 yrs old. If I were to apply a percentage, maybe 5 percent if that.

You need to get out of Michigan more often.

tobybul · #13 05-20-2006, 12:21 AM

Har di Har Har...........

I can hardly wait to get out and retire in a warmer climate. Arizona? Florida? Northern CA? New Mexico?

tobybul · #14 05-20-2006, 12:46 AM

I guess the best way to describe the take off accell on this 300D is like starting with the gear on 3rd or 4th.

Motorhead · #15 05-20-2006, 12:55 AM

[QUOTE=rhodes2010]It is true that the way we end up driving these is accelerator to the floor,
when you eventually reach desired speed, back off throttle.

Sounds like how I drove UPS trucks for 30 years
I always told people that there was only two throttle positions on a UPS truck...... WIDE OPEN

and idle!