W114

[Popeye]

Hi all,

I recently acquired a 1971 W114.011, i.e. a 250 with the M130 engine. Auto transmission. Red with off-white MBTex interior, 170k miles. Officially I think I'm the fourth owner, but one person owned it 1973-2023. Mechanically seems to be solid, paint is decent (great from far but far from great), and little rust (in trunk, I think I can fix this). Everything seems to work, including the original Becker radio and A/C - although I've not yet tested a/c in hot weather!

Tasks:
1. General technical familiarization. I found the M130 engine manual on-line, purchased the two volumes of chassis manuals, as well as the Chilton's book. I found this site seems to have great MB parts details: https://nemigaparts.com/ - are folks familiar with this site? I need to study the books and the car.
2. Carburetors probably need a cleaning. I am getting a hesitation / stall off the line (solved by a double-pump of the accelerator). I'm contemplating running lacquer thinner in the carbs (via the inlet fuel line). Frankly, despite endorsement this scares me a bit... I may try using carb cleaner at first. Or perhaps take the carbs off and "dunk" in cleaner. Not sure yet.
3. Cleaning. Nothing is specifically dirty, but nothing has been "deep cleaned" in a while. Scrubbing carpets, headliner, etc.
4. Drive it. I've put about 500 miles on it since purchasing it, but recently the weather in the northeast has turned cold, i.e. salty.

Just want to introduce myself; I'll post more as the car evolves! Happy to hear advice - I'm in a learning mode.

[Todd Miller]

Sounds like you found a great car, and I hope you'll share photos.

If possible, it's probably worth it to get it professionally detailed. They can get all the iron out of the paint, polish and seal it, and it'll look amazing.

Be careful with the headliner, as you might cause it to stretch and be sort of wrinkled, or otherwise damage it.

You might dump a can of SeaFoam into the fuel tank, and either take it for a short drive, or of the roads are currently salted don't. Just let it sit and run at different speeds for 20-30min and shut it down. SeaFoam is an outstanding product, both as a cleaner, and as a fuel stabilizer. Plus, you may have heavy carbon build up on the backs of the intake valves, causing your lean stumble when you crack the throttle. The carbon absorbs the fuel like a sponge. You can do things like make sure the mixture is a tad on the rich side, make sure that the accelerator pumps are spraying a good volume AND duration, and orient the nozzles so that the stream hits the throttle plate in a way that cause it to become sort of a big spray, rather just being a stream that shoots down through. That makes the accelerator pump fuel easier to atomize and burn.

[Sugar Bear]

Welcome! Sounds like a very nice car.

I'd start with an oil and filter change using a 15W-40 diesel rated oil for the higher ZDDP content due to the flat tappet camshaft. Then adjust the valves, point gap using a dwell meter vs. a feeler gauge and then the ignition timing. While setting the initial timing also confirm with the timing light that the mechanical advance works.

Run a couple of tanks of Shell, BP, Chevron etc. premium gasoline with a full dose of carb cleaner in every tank and then change the fuel filter.

Next with a hot engine, air cleaner off, rev the engine up to about 3-3.5k and force the choke plates shut until the engine almost stalls. Release the choke plate before it stalls and repeat this a few times. Find the vent tubes/air bleeds on top of the carbs and run cleaner followed by compressed air into them.

If this doesn't clear things up you'll probably have to disassemble the carbs clean and soak them.

[Popeye]

Thanks!! I appreciate the inputs. Once the weather dries out / salt is gone, I’ll implement your suggestions. I bought the car from the long-time owner‘s mechanic (qualified), so the basic maintenance is current (valve adjustment, oil was just changed, etc.) but the car has not been driven much in the past ten or so years.

I’ve done a full restoration on a British car (Triumph TR4A), so I’m familiar with the concept of 1960’s carbureted engines - but have a lot to learn specific to the Mercedes. The W114 is a so much more sophisticated and better engineered, it’s not even funny!!

And I can’t seem to post pictures… maybe I need a certain number of postings before I am allowed. I’ll post pictures once I can!

[subforry]

Welcome. The w114 250s are great cars. Parts are little less expensive compared to older cars. If the front and rear windshield seals are dried out, then I recommend replacing them, especially if the car is stored outside. Also new trunk rubber. This will help keep water out and slow rust.

[Tony H]

Keeping one of these outside is not a great idea. These older cars are so prone to rust. Hope it has many years left in it.

[Maki]

The carbs on these cars have anti-dieseling solenoids that can fail. When they do they default into the closed position and cut off the flow of gas to (IIRC) the idle jet. That can impede drivability. The solenoids are NLA but I've known of people who fixed the orifice in the solenoid in the open position by various means.

[Popeye]

Thanks again. It’s a garaged car, and not driven when salt is on the road! (And will be decently dried if it gets wet, i.e. drive it after a rainstorm to “blast” the nooks and crannies.)

I bought Spray Nine cleaner for the interior, at the recommendation of a vendor. I have a soft bristle brush, and will go at it slowly. Griots interior cleaner helped with some of the grime, but far from all. I can clean while in the garage; engine / carburetor work will wait until I can drive!

[cth350]

You picture issue is probably due to their size. This forum limits pictures by both the pixel count and the overall disk usage.

The tool to "force the choke plates shut" can be the palm of your hand if they are work hardened like mine. Just don't do it for long as it will hurt if it's more than a few seconds. You want something that will conform to the surface irregularities of the carb cover, flexible enough to seal, will not get sucked into the carb or get shredded and sucked into the carb.

If you are handy with carbs and will be doing your own work, invest in 2x plastic covers that adapts an air flow meter to the zeniths and 2x airflow meters that have a gauge, not the simplistic floating ball style unisyn.

-CTH

[Popeye]

Question: what is the consensus on replacing fuel lines? The lines appear to be original, or at least very old, cloth-covered lines. Should I preemptively replace them, or wait for a failure? I’m not familiar with this type of hose, but an internet search suggests replacing ASAP. Thoughts?

Otherwise I’ve spent some time scrubbing the interior. The MB-Tex cleaned up nicely. I’m not sure the official color, an ivory/light beige, which really shows dirt. Floor mats were shampooed, and now the interior just “pops”! Next up, I’ve ordered varnish amalgamator to try and restore the (presumably nitrocellulose??) varnish. The varnish is in pretty good shape, with minor alligatoring - thus hope a simple reflow will bring it back to life.

Finally, I am replacing all the accessory v-belts. A bit painful, to say the least! I have removed the belts (leaving the fan in place), ordered replacement Continental belts, and plan to install this weekend.

[Todd Miller]

It's probably never a good idea to wait until fuel hoses fail, in order to justify replacement.

[Popeye]

Originally Posted by Todd Miller

It's probably never a good idea to wait until fuel hoses fail, in order to justify replacement.

Thank you for the “nudge” in the right direction. I just ordered a bunch of parts and metric hose (not braided)…

[Maki]

One other thing about the carbs: the heat risers in the exhaust manifold can seize up, subjecting the carburetor bases to excessive heat. Over time that can produce warpage and result in vacuum leaks. Check the carbs and bases to make sure everything is flat -- and of course try to free up the riser.

[Popeye]

Alright… so I’m cleaning the carburetors.. I am working on one at a time, so that the second can be a reference for the first. My aim is to clean, inspect, and replace gaskets. I do not want to alter any of the settings.

How do I disconnect this electrical connection at the bottom?

Let me see if I can insert a photo from Dropbox:



https://www.dropbox.com/scl/fo/54webzarelrc9aezjqeu8/h?rlkey=tm8zs4tr9zmzqsuwtojtyjg07&dl=0

[Maki]

That's the anti-dieseling solenoid I mentioned earlier in the thread. There should be a connector at the end of the wire. The solenoid screws into the carb base.

Many of these solenoids have gone bad -- check for continuity between the wire and the solenoid body. If the coil inside has failed you'll have an open circuit.

The solenoid defaults in closed position. If the solenoid doesn't open when the vehicle is operating it will hinder driveability.

Replacements are no longer available. I've known people who pulled the guts out of the solenoid and epoxied the control plunger into permanent open position.