W111 carb, fuel pump, maintenance questions - PeachParts Mercedes-Benz Forum

Bcollia · #1 07-05-2008, 12:47 PM

Restoring a 1966 230S and is currently not running. I need to clean out the gas tank and start better toubleshooting once I have fuel. What advice can everyone give for "general maintenance" tips when dealing with a car this old? It was a barn find. One owner, couple purchased it new in 1966, was driven up until 2002 when the husband came ill. He just passed away this year and the wife had no more use for the car. Upon inspection I noticed the following issues that need to be addressed.

1. One of the carbs has no tension - Are rebuild kits available for these?

2. Open rubber hose at rear of gas tank coming from fill tube

3. Turn signals not functioning - They light up when the lights are on but fail to blink

4. Similar issue with tail lights - I removed both tail lights and am soldering the broken connection in the bulb housing today which hopefully solves this problem

5. Clip for hose on the radiator overflow is broken

The vehicle did not come with a key. I recently purchased W210 diesel from the dealership and when I get that serviced next week and I am going to inquire about getting keys made based off the VIN.

Also I ordered the basics. fuel and oil filter, have to look at the front brakes due to the fact there are a few variations for these, air filter etc. Anything else recommended?

I would love to find a shop manual. I seem to only find them for the 68-72. Any suggestions on places to look?

Thank you fellow vintage MB owners,
Bryan

Bcollia · #2 07-05-2008, 01:23 PM

Just picked up a service manual CD from http://www.classictechlit.mbusa.com/MB/ for $19.99! One down.

flacollect · #3 07-05-2008, 01:41 PM

Sounds like a fun car. I just bought a '67 - 250S. It wasn't running either.

First thing I did was bought an electronic ignition for it. You will need a coil and balast resistor to upgrade it. Works well. The carbs need cleaned. I used a little paint thinner. The fuel lines are old and cracking, so I ordered 25' of fuel line. The other lines worked, however, once it got warm, I noticed a leak coming close to the carb. After close inspection, the lines were brittle and cracking. These lines go directly in front of the engine as well, and heat cause gas to expand. The mechanical fuel pump needs to push 4psi. You can pull a fuel line off to the find out how much pressure is built up. Check, or change the fuel lines close to the tank. Make sure you have no air leaks. Any air leak will cause failure of the fuel pump, and if you're out driving..your carbs will go dry (don't ask how I know this 5 blocks from my house). It's a long process, but worth it in the end when it runs. My car sat for 3 years, and was a 1 owner. The brakes need redone, and the power windows need attention, but overall, it's a pretty cool old car with lots of coolness left in it. Good luck : )

flacollect · #4 07-05-2008, 01:42 PM

Check the fuses for the lights. Most have corrosion on them. It's probably a good idea to change them out. For about 10 bucks you can buy a kit on ebay.

Bcollia · #5 07-05-2008, 04:17 PM

Thank you sir, will do.

So far I am finding this thread VERY helpful.

http://www.peachparts.com/shopforum/showthread.php?t=158364&highlight=230+carb

todds · #6 07-08-2008, 01:57 PM

Yeah, I would suggest careful rebuilding of your carbs if they are sticky. The secondaries are most likely stuck in place and the insides are probably full of gunk/rust powder. The kits are available from a few sources and range from $30 to about $100 each depending on the quality/source. Check the heat risers under the carbs and make sure they move or are at least stuck in the wide open position. There is likely lots of bad stuff in the tank, I hadda have mine re-done. It was also a barn find owned by an older lady in amish country PA. I seem to be doing okay with stock ignition on mine, but replaced the points of course. I still have the original wires on it too. Idles as smooth as I could ever hope. Probably would run better with an aftermarket box but that's far down on the list of finny purchases for me.

If I had it to do over, I would've kept the carbs, metal fuel lines, etc as original as possible and skipped the $900 Webers I bought. They clogged a few times before I had the tank done. The Zeniths were absolutely FULL of rust powder (red gunk) too, amazing it ran at all before I rebuilt them.

Is it manual or automatic?

If you need tires, Firestone had some with thin whitewalls avail in 185/80r13 size, at least 2 years ago in PA. Another thing I replaced was the rubber steering coupler, besides the carbs/tank it made the single biggest difference in the car. Completely transformed the steering and handling.

ja17 · #7 07-08-2008, 10:22 PM

Hello,

The twin Zenith carbs are complex but amazingly reliable and well mannered when put right. Most owners give up on them because they do not understand them. These early versions (pre Emmision) are the best. I have a copy of the factory set up procedure I can email you if you like. All re-build parts are available. Try aftermarket suppliers and save lots. You'll need a few gaskets, the acceleration discharge pumps (early were leather later were neoprene). Replace with the neoprene will solve the leather dry-out issue from long storage. You will need the secondary rubber diaphrams, and possibly some mounting gaskets (at manifold). Run a tiny wire down the accelerator discharge tube to clear it. This tube simply is pressed into its bore and can be removed from its tappered hole with needle nose pliers. The rest is understanding the correct way to sync the carbs and set up the idle. The complex automatic chokes and cold idle adjustment will take some studying before you will realize how it works.

I am good with these carbs so just ask questions.

Bcollia · #8 07-08-2008, 11:11 PM

Excellent!!

Thank you both for your help gentlemen. JA - Yes, please email me that manual if you could. Send it to [email protected]. I have already set Todd up with an email address and if you would like one as well please PM me with the address you would like or just include it in the email.

Here are some shots of my carbs. The car was actually driven until 2002 when the owner came ill. The flap isn't actually stuck, it just doesn't have the tension a spring should be providing to keep it closed. I suppose you could say that it is "stuck" open. Just sorta flaps there with no resistance. I looked to see if a spring had come disconnected, but that was while it was still on the trailer. It is coming off this weekend and is going to Grand Rapids. I work for the Air Lift Company and one of our regional salesmen is very good friends with many members of The Relix car club. They have a garage night every other Friday and all 20+ members go to town getting stuff done to the project of the night. I went out and helped with his 55 Chevy 2 door post a while ago. The guys are pumped to work on such a unique car. Anywho...

Thanks again for your help guys. Take it easy.

Once the tank is cleaned out and pressure tested, gotta make sure the fuel pump has 4-5psi?

todds · #9 07-09-2008, 10:09 AM

That flap is one of your chokes, they operate by cutting off airflow to the primary barrel of the carb and thus creating more vacuum to draw more fuel in. They should snap shut when the car is stone cold and the accel is pressed and start to open as the car warms up. Those carbs look REALLY sludgy and tired, and a bit "mousy" as well ;-) They aren't gonna work in that state, at least not the way they were intended to. If your carbs look like that, then your heat risers are almost definitely stuck as well. These are very important, because stuck ones will overheat your intake system and warp those nice old Zeniths if you let them go. You still have most of the original fabric and rubber coated metal fuel line, I'd flush it through with something and keep it intact and replace that old rubber-only portion between the carbs. When you unscrew that line be careful, hit the threads with a bunch of PB Blaster or something first a few times, then use a nice properly sized wrench to snap it free without twisting the line. Basically, those carbs ought to come off and be re-done.

Your chokes are closed by a heated spring inside the round choke housing on the side of the carb held on by 3 screws on a hold-down ring. The housing rotates for seasonal/engine break-in adjustments. This internal spring is heated by an electric element when the ignition is on, hence the wire plugged in the side. There is also a fast-idle cam with 3 or 4 steps inside there which holds the throttle open a hair as well (after you pump it once). In addition, your accelerator pump should give a nice sharp squirt visible underneath those flaps when the throttle is pumped. All these things, the carb internals, plus the ignition system and battery have to be working right to get this thing started. Once they are, it'll start like a charm every time.

Your first steps would be to find out what's in your gas tank, if your fuel pump is okay, and tend to the carbs. Then you'd need to take out your spark plugs and drop some oil or something in there to get some lube to your cylinders/pistons which are hopefully not seized. You can jack up a rear wheel, put it in gear and turn to spin the engine by hand if it's a manual. Make sure the oil in the engine is good. Then clean the plugs and put them back in with the wires off and crank it with the starter. After it spins, see if you get spark when cranking, if so, plug the wires in and see if it fires! It would probably smoke like hell and run like crap for a little but it'll clear. Once you get it at least firing you can tend to the ignition/points. This is all assuming you've remedied your carbs first.

This is just the engine, you've got brakes, cooling system, and greasing the suspension to deal with too. The plus side is that they are easy to work on, well designed, really enduring cars. All of it is do-able and really not that hard, and the results are worth it! Have fun! Did I forget anything?

Bcollia · #10 07-09-2008, 11:51 AM

Todd, I will follow your instructions to a T. I just received my electronic manual from Mercedes. I plan to get the car home tonight and begin following your instructions. I have ordered new filters, new coil, new brakes for the rear (there were three seperate ones listed for the front so I have to measure the caliper), new plugs, wires look newer, and the guel tank is empty. I'm lowering the tank tonight to check it over and completly clean it out. When I went to pick the car up the guy showed me that it turned over so good news is that it isn't seized. Would you recommend a place to send the carbs to get redone or do you think this could be handled by a lowely weekend wrencher like myself. I will post progress photos tonight as long as I am able to get her home.

Thank you again and again for your expertise and advice Todd.

Wish me luck

todds · #11 07-09-2008, 02:52 PM

Quote:

Would you recommend a place to send the carbs to get redone or do you think this could be handled by a lowely weekend wrencher like myself.

Hah, "You can do eet!" It's not really difficult to do, but you need a big space to spread everything out where it can't be disturbed and need to be meticulous with all the little bits n' pieces. For the most part nothing will fit where it doesn't belong, with a few exceptions. It helps to have a basic knowlege of how a carb works but it's not really necessary if you trust yourself to put everything back where it goes. It's handy to have a bunch of little trays or baggies or something and document where every screw and washer goes. It's kinda like a big puzzle, if you've ever taken a clock apart you're way ahead of the game. Don't force any of the screws or attachments, be gentle with it. You want to remove all the plastic parts and dip only the metal.

You'll need an assortment of different sized flatheads, a carb cleaner dipping bucket which you can get at autozone or any other parts store, a can or two of carb spray and some thick chemical gloves and of course a couple of decent carb kits.

Another great reason for doing it yourself is that you will have an intimate knowledge of what exactly goes on in there and this is invaluable in tuning and troubleshooting what can go wrong down the line. You could end up paying techs many thousands of dollars along the way for diagnosing something that you would know about before even opening the things up!

Once you get them back together you'll need a unisyn and adaptor (cool whip container?) to balance them and some info on initial adjustments. There are plenty of other threads here about rebuilding Zeniths which explain some of the trickier things which you hopefully won't have to deal with, i.e. warping, vac leaks, etc, ya might want to check them out.

wbain5280 · #12 07-10-2008, 12:47 AM

Here's a link that will help you with the carsb.

http://jaimekop.com/CarbManual/index.html

which is available at the top of this forum:

http://www.peachparts.com/shopforum/forumdisplay.php?f=12

Bcollia · #13 07-10-2008, 01:42 AM

Quote:

Originally Posted by todds

Hah, "You can do eet!"

Damn right! Atleast I hope so. No.... "I can du eet!!" My fiancee and I got this car to do everything (or as much as we car) by ourselves. I've been a fuel injected man my whole life. Only other carburated vehicle I've owned was a 1965 Cadillac. I have to say that German engineering makes me more confident in being able to handle the Zenith.

Thanks for the link Bain. I had run across that and printed it out as a supplement to the Star Classic Service Manual. Also if you want a vintagebenz.org email address, shoot me a PM.

We got the car home tonight. Brakes worked great lowering it out of the trailer. That was a relief. I'm heading into the dealer in the morning to get the key cut. Said they just needed to see a title and $15. Well I gotta catch some shut eye after spending the entire day installing/battling MicroSoft Exchange service. Compared to that I'm sure these carbs will ne cake!

todds · #14 07-10-2008, 10:35 AM

Quote:

Only other carburated vehicle I've owned was a 1965 Cadillac.

My first classic was a 67 hardtop sedan deville, black, "with some slight rust coloration" Next came a 67 sixty special. I got to know those 429's pretty well, mine had a steady diet of exhaust manifolds. After I got sick of trying to keep those cars in their lane on the highway I ended up in a cheap white Alfa Duetto, also a 67. At the time I wanted the polar opposite of a caddy. I never knew rust like that before! I appear to be stuck on 1967.

The mercedes is the first classic that's just felt "right" to me, a good mix of everything and I've gotten it to run better than my caddies and alfas ever did. I could never get the caddies to idle smoothly when hot or stay quiet at the exhaust flanges, having only two bolts to hold the pipes on. The alfa was another story with poorly converted webers that liked to idle above 1000 and the worst choke operation of any carbs ever. Due to the short tripping I had to do they lived half their lives warming up and coughing spitting and stalling. I actually considered down-grading to the earlier alfa downdraft solex at the time. Compared to that, the Zeniths are very well behaved, but many other people have been frustrated by them.

Bcollia · #15 07-12-2008, 12:01 PM

Well gentlemen, I'm heading out to the garage until I can get that puppy started. Wish me luck.

I was able to order my keys from the dealer yesterday. $53.00 for the set of three. Now I would like to get new gaskets for anything that is recommended as well as a carb rebuild kit. Where is the best place to get these? I'm gonna check Fast Lane of course, but do have to price shop so I can get the best of everything I need. Any advice and direction is appreciated.

Well off to the garage!