Absolutely glacial 240D .. what am I missing
 

1972 220D 4 speed manual with later model 240D engine swapped in. Unknown miles.

Motor runs smooth, starts first thing in the cold. Have not checked compression but the motor does not consume much oil. On par with my 82 240D that is much quicker. Burns about 1qt / 1500-2000 miles. Motor has excellent oil pressure. It's basically at about 3.5 bar at hot idle coming off the highway. I'm presuming the motor is in great shape.

The throttle linkage has lots of slop, but when I have someone floor it inside the cabin, all the slack is taken out in the engine bay.

One thing I've noted is that the throttle linkage does not reach the full throttle stop on the injection pump. Even if I disconnect all the links and move just the injection pump arm, it does not reach the full stop. Also the injection pump won't let me manually shut the motor off.

Whats been done:

- New fuel lines (no air leaks)

- New fuel filters

- Tank removed and power washed out, screen removed and cleaned

- Injectors replaced with known good units from another 240D

- New air filter

- valves checked and all within spec, motor oil and filter changed( not that that part would matter)

Symptoms:

Absolutely glacial acceleration in comparison to my 82 240D AUTOMATIC. I would assume the w123 with automatic trans is a heavier car and therefore slower. That car has about 165k miles on it.

Car struggles to climb hills in 3rd gear and will lose speed on the highway in 4th cruising around 65/70 at the slightest incline.

Checked brakes and none are dragging. I'm stumped as to what could make this car so slow. I thought the 4 speed would make it a touch peppier than the auto w123. It is noticeably slower.

240d are slow. Incline should be fine but, is the tank screen replaced as well?

I'd be looking to fix all the slop in the throttle linkage and find out why the IP lever won't hit the full travel stop. If you're not getting full travel when you push the lever manually and you also have a bunch of slop in the pedal linkage, you're probably getting even less throttle from the pedal. Lack of full travel = lack of full power. On an engine that had ~65HP when new, you need all the power you can get.

The 220D is less powerfull Engine then the later models.

When I got the Car on my Year and model acceleration was extremely bad but once speed was built up it drove normally. When you slowed down to a stop the acceleration issue was back.
It turned out the throttle linkages were extremely sloppy and the throttle lever was not getting moved far enough.
In the Mercedes Service Manual there is specific lengths for the linkage rods and is a few parts back to the acclerator pedal that can wear out.

More recently I was having inconsistence acceleration and the linkage on the fire wall was in bad shape. Replacing that fixed it.

I thought your year and model had a Fuel Injection Pump with Butterfly Valve that controls venturi vacuum in the intake Manifold and a Fuel Injection Pump with a Pneumatic Governor that has a Diaphragm inside.

If your Diaphragm has a vacuum leak you would get smoke because that causes more fuel to be injected.

However, over time the Diaphragms get stiff. I am not sure what symptoms that would cause. Also one side of the diaphragm is exposed to the air and if the vented cap is restricted the Diaphragm cannot work correctly. (Just remove the vented cap and drive and see if there is a change.)
There is threads on replacing the diaphragm.

Restrictions in the tubing to the Venturi.

Lack Of Pep
 

You already found and ignored the problem : the IP isn't reaching full throttle, this is a very serious issue and why I was able to buy my cherry '82 240D for $1,000 in the middle of the Diesel Mercedes craze some years back ~ it barley went 60 MPH on the flat freeway and couldn't go up any hills except in second gear (automatic) with the throttle pinned .

First, disconnect the _vertical_ throttle rod at the IP and figure out if the IP has some binding issue or not, then go through the various pivots and firewall bell cranks etc. and clean and lubricate each one, a little bit of slop anywhere in the throttle linkage results in lack of power and lower top speeds .

Yours sounds like totally screwed up linkages .

A 240D isn't fast but it shouldn't be sluggish either .

It should drive sprightly .

Okay so heres the thing. I have had someone sit in the car and press the pedal to the floor and it is "floored" in the engine bay. So it's not like someone is flooring it but its only at half throttle or something.

Secondly I have a feeling some PO or mechanic could have messed with the full stop on the IP pump. I say this because when I disconnect ALL the linkage to it and simply move it by hand, it does not go all the way to the stop.

So what I'm saying is that while I realize the linkage being sloppy isn't helping anything, I do not believe it is hindering the car from reaching full throttle. Either something is messed up in the IP itself or someone simply turned the full throttle stop in too far ? I'll take a photo or video and post what I'm talking about for clarity.

Sorry I did not notice the " later model 240D engine swapped in. Unknown miles"

Do you have an MW type Fuel Injection Pump or a M Type? The Governor is different on the MW compared to the M type. And Ya I know the on both the throttle lever is still supposed to rest on the stop on both of them.

Note on a 240D but one of our members with an M type Pump changed the manual shutoff lever shaft O-rings and got something wrong. However, I can't remember the symptoms.

Got it any why I said # 1 : disconnect the vertical linkage rod and then see if the TP goes to full throttle stop or not .

Then, figure it out from there .

-Nate

If there is a linkage to the Shut Off Lever disconnect that and manipulate the lever and see if that changes the position of the Throttle Lever.

Note that the MW fuel injection pump dose not have a seperate shutoof lever.

To answer your initial question, horsepower. :D


Dan

Are you saying he should get some Horses and hitch them to the Car?:)

Okay,

photo for reference. Here is how far from the stop the lever on the IP pump is, regardless of throttle linkage being connected or not.

Would this suggest something within the pump is messed up?

https://i.imgur.com/LHM7PXS.jpg

IP Not Closing
 

The vertical rod appears to be connected in this photo.....

Be careful here before making any changes, disconnect that vertical rod at the bottom and if the gap is still there then yes, you have a problem, it *might* be as simple as the shut off valve is incorrectly connected inside the injection pump .

To re connect that vertical linkage rod, use a long flat screwdriver and gently apply pressure whilst moving the pivot .

Remember to clean _all_ the rust and crud out of the pivot cup and lubricate it before re assembly .

Okay this sounds like perhaps that is the case since if i disconnect that rod it still stops in the same place.

Also, I can not shut the motor off with the throttle stop in the engine bay, even if I disconnect the linkage I can't pull the throttle up enough to stop the engine.

O.K., the shut off pod is held on by 10MM ATF bolts, BE GENTLE and remove it then see if the lever goes to the stop ~ if not, look up from below and make 100 % sure the IP's linkages are not touching the body, or oil cooler pipes etc., etc., one you're 1,000% CERTAIN everything external is good, replace the IP, time it and motor on happily .

240D IP's are not $pendy as not many still want these cars .

FWIW, _I_ was able to change and time the IP in one of my OM617's so if I could do it I think pretty much anyone can .

? Where are you located ? .

Adding this to your profile so it shows helps get others near you to offer help and parts .