No it doesn't. Need more power that is. The rest of the world needs to take a chill pill. Nice to hear it's coming along. I'd love to have one of thes old squares. They appeal to me more and more the older I get.

- Peter.

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2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

Is your pneumatic injector pump diaphragm holding vacuum? Both the diaphragm and the hard plastic (not rubber vacuum) hose are key to proper operation and fuel delivery. If you need to replace the hose from the plenum to the IP, use PEX pipe, not a rubber vacuum line. The rubber line will flex a bit and can cause "sawing" effect in your idle. You'd need 6mm inner diameter PEX and a heat gun to properly get it on the barbed fittings. The heat gun helps with making a permanent bend in the pipe as well a couple inches above the IP, to match the stock pipe shape roughly. It's not necessary, but is much neater this way.
If your diaphragm isn't holding vacuum, it needs to be replaced. Until then don't bother making any adjustments to the linkage.
Other than this, you're not going to get more power from that engine. It's not a muscle car, nor even a fast car. Treated right though, it will outlast you. IMO, the 4cyl W115s handle better than the 5cyl ones, probably due to the extra 300lbs in the 5cyl sitting on the same suspension as the smaller engine.
Learn how that transmission shifts and it will be a great car, with plenty of power.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Thanks Phil
my next step is to look at some bozio or monark injectors.
the glow plugs have been replaced as well..
as for injection pump , my mechanic advised this is a very expensive thing to repair , considering the 240d wasnt sold in huge numbers in Australia.

Have you replaced the IP oil?

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Hi Phil
to be honest i dont know when the oil inthe IP was replaced...
engine oil was replaced around 3 months ago

You should have a red plastic cap (or formerly red due to 50 years of exposure to everything in the engine bay) on your injector pump a few inches aft of the injector lines. Unscrew the cap and stick in a small diameter vacuum hose attached to an aspirator tank on a handheld vacuum pump, like a MityVac.
Suck out all of the old oil which will probably smell like paint thinner and be a nasty black color.
Once you get this fluid removed, find the fill-level bleeder bolt in the side of the IP. This bolt takes a 14mm hex socket and has weep holes which should become visible after you unscrew it about 3mm. You'll find the bolt about halfway down the side of the IP. Don't unscrew it completely, just enough that you can see a weep hole in the shank of the bolt near the head and the sealing ring.
Use a funnel and pour in a couple ounces of clean motor oil until you can see it dripping out of the weep hole in the bleeder bolt. Tighten up the bolt snug.
While you have the red cap out of the IP, clean it with some decent solvent like fresh diesel or brake cleaner. Make sure the vent holes are clear in the cap, then replace and run your engine.
This process needs to be done with every oil change but since you're rescuing this car, you may need to do it once every few hundred kilometers because your IP will be sloughing off old crap inside with the fresh oil and cleaning itself as it runs.
While you are at it, you may want to rebuild the lift pump, if you haven't already. It's an easy rebuild and there is a great kit available from a guy in the UK with the exact o rings and gaskets you need. This rebuild will prevent fuel from leaking from the lift pump into the IP.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

I took the red cap off
but couldnt see any oil in there ... is that normal ?

There's only a few ounces in the sump at the bottom of the IP. You won't ever see it and will have to use some kind of suction device like a mityvac with aspirator tank, to get the old stuff out. There is a sump drain plug but it can be hell to get loose and then back in properly.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

So another update
things are not going so smoothly...

Took it to my mechanic, who ran an injector and fuel line cleaning solution through it about a month ago.. They also fixed the air conditioning ( just a regas) , perfect for the hot Australian summer.

It was driving fine , but my driving is mostly city based , where the stop/start traffic is common and speeds dont go over 80km/h ( or 50mph )...

however , the last two weekends , ive need to drive along the freeway to visit horse stables/yards. this involves a drive of over 90 minutes with speeds around 100kmh (60mph). and with low gradient rolling hills..

The car struggled to climb and hold speed ( actually went backwards by over 30kmh ) and temp gauge was rising steadily... got brief respite when descending.... got to my destination and noticed the crank case vent pipe had blown off and could see a lot of oil vapour coming out of the breather outlets... It fees like it really laboured going and maintaining that sort of speed

Is this the telltale sign of worn engine and blowby ?

Vapor is normal, blowing the breather off isn't. It does indicate blowby. It probably gained some power when the breather disconnected relieving crankcase pressure. Blowby can be worn out rings and/or pistons OR it can be stuck/clogged rings. The real test is a leak down test.

I'd try chemically soaking the rings, using something like AutoRx, then run synthetic oil. Get it hot and run it hard.

The power loss could be fuel related such as poor fuel or clogged filters.

How high did the temp go? How steep and long was the grade? Dropping speed w AC on on a steep hill is normal in a 240D.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

G'day!

A] I second Auto-RX - and would follow instructions to the letter. It removed blowby entirely on my 300D but didn't on my 240d. It did improve compression in both vehicles though.

B] I would also recommend you use Liqui Moly MOS2 15W40 in the injection pump (and in the motor after Auto- Rx treatment completion)

https://www.youtube.com/watch?v=rh0PtXwZo_Q

C] Bosio injector nozzles sold here:

https://kermatdi.com/i-904-bosio-mercedes-late-om-616-617-single-nozzle.html

D] Injector Rebuilder here (I'd get your lift pump rebuilt too, and purchase the OFV spring):

https://dieselfuelinjector.guru

E] My W115 restoration journey here:

http://www.peachparts.com/shopforum/diesel-discussion/398899-w115-owner-advice-needed-buying-1976-240d-6.html

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html

Unlike most car engines. Every horsepower that engine can produce will frequently be needed.

Three issues very common to the 616 cars. Have someone push the accelerator pedal to the metal. It has been there before. Have a look at the same time the linkage is getting the arm on the injection pump to the stop.

Close off the return line from the relief and overflow valve.Huge difference or no difference the spring tension in the valve will need a tension check or there are other issues.

As the timing chain stretches with use over the years. This naturally retards the injection pump timing. Wise to also check the timing chain as well for too much stretch.

Going up a pretty good long hill. Even with a perfect engine and a manual transmission. If you lose speed. For example catch up to the car ahead and slow down. In general you cannot gain the lost speed back.

A reasonable test in my mind is to find the 0-60 time of this model. See if your car can do it. If it can the checks probably will not be required. If not they should be done.

Engine worn too much? The na engine should be a managable swap. fortunate for you perhaps many might have come with manual transmissions in Australia. You also want the rear end from the vehicle that has had the 5 cylinder.Maybe they even exported the five speed manual transmissions to there?

It may just be me but I preffer the way the 616 handles over the 617 cars. I find that I have to drive them and that may be part of the appeal.

the hill isnt a high gradient ( between 5 and 10% ) , but it is long...
the temp was getting close to 100. usually it sits around 80 when travelling on the flat plains.

oil pressure was all the way up , but when i turned off the freeway and came to intersection for a stop, it dropped down to 2.

the aircon was not on at all during these long drives.

Manuel transmission mercedes are very very rare in Australia... after 1970 most mercedes were automatics.
The om617 was available in the w123 here , and only in automatic variant

Those temp and oil pressure changes are normal.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Be sure not to lug it. Keep the motor singing a happy tune. The fan is vital if the speed is not too high.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.