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Weber DCOE40 18 info needed


Mikez31ss

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I got my car the last part of November and I've only got to drive it maybe 5 times so it's still new to me. The PO owned the car for 15 years but he was pretty much clueless about the car. It has Weber DCOE 18 carbs. It's a bitch to start and takes a long time to warm up. Once it's warm it runs great. Throttle response is smooth. No stumbles or bog anywhere in the RPM range.

The chokes don't appear to be hooked up to anything. I'm posting a pic below with red squares around what I think are levers for the choke plates. It looks like there little clamps that would be used for a cable to each lever... kind of like a bicycle brake or shifter cable. How is the choke mechanism usually set up on Webers?bcrumb.jpg

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When I ran webbers on my daily driver way back when. I modified the stock cable to work with the webbers. Another option is to use a universal choke cable and rig up something like the pull for the fresh air vents that are at the drivers left knee and the passengers rt knee.

 

You may be able to get away with just runing the choke cable to one or two carbs and be OK.

 

Try moving the choke lever on one or two carbs and see how it starts.

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The levers you're showing are for the chokes.

On my setup, I had to start with the choke on depites of all the comments I'd got from many people telling me on DCOE is not necessary to have them to start the car.

the setup was a L28/N42 with quite high compression for street use (10,3?) that could explain why cold start was difficult too.

 

See below a picture of my engine bay, choke cable is a very regular cable, similar to the ones used on bikes for brakes, hooked up under the dash as described on the post above. It is very straight forward installation (in addition to an unexpected good anti thieft device :icon45: ).

 

p2709011.jpg

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Thanks all. Matt...do you have a closer shot of that setup?

Also more questions: You notice that plate under the carbs? Heat shield maybe?

And in that pic you can see leakage. That pic was taken just after the car was delivered. I wasn't there when the trucker unloaded my car but the PO had given him a can of starter fluid which he apparently used liberally. I wiped the plate down later and noticed staining under the area where the carbs mount. Should the gaskets be replaced or maybe just torque the nuts down a little more?

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I've had two different sets of triple Webbers on several different cars. I never had the chokes set up on any of them - even the daily driver 240 I used to drive. I just pump the pedal to get a couple of accelerator pump shots and turn the key. If it is cold sometimes I have to feather the throttle a few times just for the first few seconds of run time.

 

The only time it is a little hard to start is if it has been sitting for a few weeks and the float bowls are empty. Because I only run a mechanical fuel pump I have to let the starter turn over quite a few times to fill up the float bowls before I can pump the throttle to start.

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The levers are NOT 'chokes'---that is what inhabits the throttle barrels!

 

The levers are the 'starter system' for the Weber. It's a separate circuit that allows fuel to be siphoned directly from the bottom of the float bowl and mixed with air with the throttle plates closed to get the car initially started and idling. With the levers engaged and the foot off the accelerator, the car should start and idle at about 1500-1700 rpms.

 

Once it's started, the lever is moved back to 'off' and the car can idle to complete it's warmup. It doesn't function like a 'choke plate' at all, in that once the throttle is depressed, there is insufficient vacuum present in the circuit to allow its function, and the carburettor reverts to the other circuitry in it to run the engine.

 

If you can pump the throttles a couple times and drive away, you're so rich it's not funny, and you're loosing power!

 

Calling the lever 'the choke' is another 'freeze plug' moment with me, it's just plain wrong. Same goes for SU's on the 240 except 73 & 74...

 

Proper terminology, standardized, helps everyone understand things. It's why most engineering texts or papers have as their first section 'glossary of terms' so everybody knows what is being discussed before they start reading, not figuring it out as they go along.

 

Cheers!

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Tony,You're very sensitive with vocabulary ;)

I use to call the starter system the "choke" since it is what is written on the lever in the cabin, that's all!

I also add some translation discussion between choke & Venturi, so I understand your concern.

Regarding how the system works, we're on the same page.

 

Mike, the plate is a heat shield to avoid issue because of exhaust manifold heat (vapor lock for instance).

For the leak, difficult to tell. It looks greasy to me. it could be many things, it is hard to tell without being in front of the engine. It could also be the carbs fouling out some gas (because of bad timing, too high fuel pressure...).

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Ok first off I appreciate the help. I don't know jack about carbs and dealing with three seems like more trouble than it's worth. I know...I need to get the Weber book and learn about these things and how to use the syncrometer too.

...Tony, what activates the starter circuit when it's installed and working properly? Or maybe the question should be what makes the system engage? And disengage? And if I understand correctly the gas pedal should not be depressed before starting the car.

One more thing. You said

Once it's started, the lever is moved back to 'off' and the car can idle to complete it's warmup.
As soon as the motor starts the levers go back or after the motor starts getting warmed up?

 

Matt...that is starter fluid I'm pretty sure. I've still got the can but I haven't used it myself. The stuff has a peculiar odor. The PO used it on a regular basis. And he instructed the transport truck driver to use it whenever he needed to start the car. I can look at the plate and see baked on stains directly under each carb where they meet the intake manifold. The front carb has a lot more staining than the other two have.

I've never heard any backfire through the intake. The car runs great once it's warm.

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Take a look at your photo again. There are three bolts and bosses on your intake manifold. Those are usually used for mounting a throttle linkage kit. The fist boss towards the front of the car, close to the thermostat, is a perfect place to mount a stud with a rocker arm. Connect one end of the rocker arm to the choke levers (cold start levers) of the carbs, and the other to your stock choke cable. The rocker will reverse the action of the pull cable and pull the carb levers open. Kind of like a "see-saw" with its pivot on that one bolt

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:shock:

I hope you don't start or run the engine as seen in the first photo!!!

I'd hate to hear what would happen if the air cleaner retainer screw(center carb) got loose and went down a venturi!!!

The same goes for the speed nuts.

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Take a look at your photo again. There are three bolts and bosses on your intake manifold. Those are usually used for mounting a throttle linkage kit. The fist boss towards the front of the car, close to the thermostat, is a perfect place to mount a stud with a rocker arm. Connect one end of the rocker arm to the choke levers (cold start levers) of the carbs, and the other to your stock choke cable. The rocker will reverse the action of the pull cable and pull the carb levers open. Kind of like a "see-saw" with its pivot on that one bolt

That's the only thing I can think of too. I'll have to look under the dash to see if the original cable was kept or if it was cut at the firewall.

 

:shock:

I hope you don't start or run the engine as seen in the first photo!!!

I'd hate to hear what would happen if the air cleaner retainer screw(center carb) got loose and went down a venturi!!!

The same goes for the speed nuts.

I don't but the transport driver did. No ill effects as far as I can tell.

One of the screws was missing though ;)

I had a spare screw that fit though. Sometime in the future I plan to replace those with studs and wingnuts or wing screws anyway. Getting a screwdriver in there is a pain.

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