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1984 300D
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Discussion Starter #1
Hello everyone,

This is my first post. I just bought a 1 owner 84 300D Turbo with 149,000 miles and I'm loving it. This forum is such a great resource! I've found a ton of info about my car on here. One problem I'm having is that my car is ridiculously slow. I mean 24 seconds from 0-60. I think I may need to adjust the bowden cable. Also I should probably check all the linkages to make sure I'm actually getting full "throttle" when I punch it. The car shifts a little hard from 1-2 but not too bad and it seems like it goes from 2-3 really quickly after getting into second gear. Also, when it's floored it only shifts at around 3500-4000 rpm. The bowden cable has some slack so I guess the first thing is to take the slack out right? If anyone could point me in the right direction I would be really appreciative.
 

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84's 300TD Turbodiesel
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Hi.
Equally same problem here. 84's turbodiesel.
I'd start with the valve clearance adjustment. After this one the difference is big.
Check a throttle linkage condition. This one is good for sensitivity of acceleration.
Then check the EGR valve. Then vacuum system, hoses, valves, vents etc. Leaks must be eliminated.
Then clear the pressure line which goes from intake manifold to ALDA capsule on injection pump via overload protection valve (one can find it next to brake drum). You'll see the tapping place on manifold by means of banjo bolt.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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^Good advice.

There is a rubber throttle bushing on the fire wall, have someone press the go pedal while you inspect it to make sure it's not cracked and is operating as it should.

This can be done without the engine running, the fuel pump is mechanical.
 

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1984 300D
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Discussion Starter #4
Thanks for the advice I'll get to inspecting everything ASAP. I was noticing that the clear pre-filter on the fuel line was blackish and I could see small air bubbles coming through the input side and collecting at the top of the filter. This is signaling a big red flag to me. The car has no power from 3000 RPM and up, which leads me to believe that as the fuel demand increases, the plugged filters are restricting and not allowing enough go-juice into the injector pump. I think I'm going to start with changing the fuel filters (spin on and pre-filter) and the small rubber fuel lines and see what happens from there. Sound good? Thanks for replying.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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A bubble in the primary filter is normal. The black stuff are critters that live in your tank, they can be treated with a fungicide.

New filters are a good idea.

Check that ALDA line, if it's clogged, it's sending a signal to the IP to not supply enough fuel, so the turbo is not being utilized.
 

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84's 300TD Turbodiesel
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Thanks for the advice I'll get to inspecting everything ASAP. I was noticing that the clear pre-filter on the fuel line was blackish and I could see small air bubbles coming through the input side and collecting at the top of the filter. This is signaling a big red flag to me. The car has no power from 3000 RPM and up, which leads me to believe that as the fuel demand increases, the plugged filters are restricting and not allowing enough go-juice into the injector pump. I think I'm going to start with changing the fuel filters (spin on and pre-filter) and the small rubber fuel lines and see what happens from there. Sound good? Thanks for replying.
This filter problem should occur on cold weather conditions. But it's recommended to change both filters during 5000 miles maintenance and you're off.
I've red that it's a peak line of turbo charger around 3200rpm, so I can't wait for result You're going to achieve. Please, do not hesitate to report on it.
Meanwhile, I am stuck on my EGR valve research...
 

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1984 300D
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Discussion Starter #7
Changed the filters and it drives like a new car :thumbsup:. 0-60 time went from 24 seconds to 12. I think I'm right on par for how these cars drive. The filter was so clogged it was incredible. I'm glad it was an easy fix. Next job is to mess with the bowden cable for the shift points.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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Whoo Hoo!!

Yeah, that's a normal 0-60 time, to stay in each gear longer, back out the white plastic nut. The transmission will shift at different points depending on how aggressive you are with the go pedal. I have mine backed out to where it shifts at ~4300 rpm, the place where the engine makes the most hp. I have to lift at 55 for it to shift into fourth.
 

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1984 300D
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Discussion Starter #9
So she's back to clogging up. The clear primary filter is plugged up with black crap again. I think I'm gonna have to pull the tank and clean it out to fix the problem.
 

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W108 250s '67, w123 280ce '77, w123 300d-t '85, w126 300sd '85', w140 s600 '94,w210 e230 '97, bug69
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Have your tank cleaned, there fungi already living in your tank, the best way is to cut the tank to access it and scrape out all the gunk, at least that's what I did with my 300sd and 300d, both have been bugging me with black sludge, but now they are really clean,I also recommend using biodiesel and fuel additives, they can lessen sludge development in the tank
 

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I there a way to by-pass the accelerator linkages and make the throttle into a cable type one? I feel the linkages restrict the full opening of the throttle and robs the car of power. I want to increase my 0-60 time from 30 seconds to 25. LOL!
 

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1982 300D Turbodiesel 212K or so, it doesn't work anymore :-)
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216 Posts
if your 0-60 takes that long, then something's seriously fouled up...try cleaning the alda lines both at the alda on top of the ip and on the rear of the intake manifold...also make sure your boots that run to the switchover valve aren't busted...mine were it made one hell of a difference...

check your fuel filters as well...

i run 0-60 in about 11-12 secs...not screaming but not as bad as you describe
 

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Do you also drive a 200d ? The time I said was even on a downhill...lol.

My car is notoriously slow off the line. But once it is up to speed, it can cruise at 60 mph the whole day. I just want it to be more responsive on first gear that's why I thought of asking about the conversion to a cable type accelarator.

Thanks for the reply man.
 

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2001 Volvo V40
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Do you also drive a 200d ? The time I said was even on a downhill...lol.

My car is notoriously slow off the line. But once it is up to speed, it can cruise at 60 mph the whole day. I just want it to be more responsive on first gear that's why I thought of asking about the conversion to a cable type accelarator.
What kind of 200D do you have? the 60hp or the 55hp (february 1979 was the changover month)? is it an automatic or a manual?

Changing to wires doesn't change a thing, the accelarator linkages should be able to put the pump in full load (or open the valve in the intake manifold). If not, some adjustment is necessary.
 

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It is an 81 manual. I guess it has the 60 horses.

I just want to maximize all 60 of them during accelaration. I dont really expect whiplash acceleration. Just a decent start up run in first gear and a little more punch when overtaking.

A friend of mine suggested putting an electric fuel pump from the tank to aid in fuel delivery. He argues that fuel starvation in an otherwise healthy engine is one of the main causes of poor performance. What do you guys think?
 

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2001 Volvo V40
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It should do 0-100 km/h in 27.4 seconds, 0-60 mph is a second or two faster.

An electric fuel pump doesn't improve power. The lift pump provides fuel under low pressure to the high-pressure area of the pump. If that fails (if the lift pump doesn't provide enough pressure) the engine will not run properly. Fuel delivery is restricted to the size of the pump elements.

Check whether the lever on the pump reaches the full-load position if you press the accelerator pedal.

Maintenance has to done: valve clearance, fuel filters, air filter. The injectors have to good and injection timing must be correct (26 degrees BTDC). Timing chain stretch can affect power on a 200D.

If you want to maximize all the hp, you'll need to rev the engine up to the marks on the speedometer, that will mean 4400 rpm (= max. power).
 

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W108 250s '67, w123 280ce '77, w123 300d-t '85, w126 300sd '85', w140 s600 '94,w210 e230 '97, bug69
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Dont install an electric pump, someone already tried that on a 240td and it just flooded the injection pump as the engine can only burn what it needsto burn to run, and excess will go back to the tank via the return line, a cheap was to improve acceleration is lessen the cars weight remove all unnecessary objects on board,have the valves adjusted to proper specs, add a little fuel additive, make tires 32psi,
 

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1982 300D Turbodiesel 212K or so, it doesn't work anymore :-)
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Bitoy...my bad i thought we were still on the original car...
 

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No harm done neosama. All suggestions and opinions are welcome.
We are never too old to learn.

Thank you for all your replies and enjoy the holidays.
 

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money pits of various forms
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No harm done neosama. All suggestions and opinions are welcome.
We are never too old to learn.

Thank you for all your replies and enjoy the holidays.
I recommend removing all the doors and interior except for whats needed. This will get you a good 0-60. Otherwise, look for a new car if you want to go fast. Even a 240d is fast enoguh, atleast for around here.
 
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