Early cold start valve 220se 61"

[Domxdc]

Hi guys,I'm looking diagram of parts for early cold start valve in 220se 61" w111 .
Mine is leaking or sometimes jamming and I don't know does it has correct washer on plunger etc.
Is any rebuilding kit still available?
Bosch part 0437900001

[wwheeler]

Boy thats a tough one. That is the same style CSV as my ‘60 W128 220SE Ponton engine. I am not sure what year they switched to the newer style that you more commonly see.

They didn’t make that many of those and almost impossible to find NOS. I was able to take mine apart and get it to not leak. This CSV operates differently from the later versions. The later version has a solenoid that extends its rod when energized. This one, the solenoid draws the metal rod up into the solenoid.

rebuild kits and solenoids are not available. But you should be able to get yours to work. The seal is made between the brass end of the long pointy rod and the brass seat that is held in by the threaded fitting. You should be able to use valve grinding paste to renew that. You will also want te remove the solenoid because there is an O-ring under there that seals the fuel.

On this model, the spring returns the metal rod back on the seat when the solenoid is deenergized. But it ALSO keeps the the seat closed during normal operation when the fuel pump is running. There is a direct line from the fuel filter to this CSV. That pumps runs at 12 to 14 psi. So that spring has to overcome that force. It is possible your spring is too weak and the pump pressure is slightly lifting the seat off and creating a leak. Springs do fatigue overtime especially when under a constant load like this one.

On the later version, the pump psi acts on the seat to keep it closed. No doubt they discovered the issue and redesigned it.

I have an injector tester and found my spring to be marginal when I put 14 psi on the CSV. So I found another spring on line that had a greater spring force and held to 20 psi. The CSV now holds solid and never had an issue since.   

[wwheeler]

I don’t remember what the red ring is for or if mine even had that. It would seal the fuel from leaking past onto the threads on the fitting if it did anything. I just don’t remember what mine had or if you need anything at all. I am away from the CSV for a few days. Should be easy to figure that out though.

[Domxdc]

Thanks guys for your support, I have replaced this moving ring washer with thin O ring and so far so good,not leaking,.
I have another question about cold start magnet fitted on fuel injection pump with two wires attached,
I've read is working like choke in modern cars, mixing air fuel ratio.
On mine there is no any voltage on it,no clicking sound ,even when cranking engine,what's energising that magnet solenoid??
fuses OK,relays OK.
Haven't got any good wiring diagram for it.
Thanks.

[wwheeler]

There will be a relay that activates the starting magnet when the engine is cranking. These systems changed a bit through out the years, so your best bet to start is looking at the tech manual under fuel injection.

The cold start magnet changes the injection pump to full rich when the engine is cranking. Not really a choke. What you are thinking about is the warm up device and is housed in the tall cylinder next to the start magnet. Its function can also be found in the tech manual. It regulates the air fuel ratio through the warm up cycle just as a choke.