W111 220SE 1963 Throttle linkage

[PeterPortugal]

Hans,

Just remembered...in order to fit the one which sits above the spark plug wires you have to remove the end piece from the linkage. The part with the ball to connect the fuel pump linkage rod. That was fiddly, a small pin retains it and you need something of really small diameter to drive it out.

Regards

Peter

[hansr433]

Thanks Peter.

Would anyone following this thread be able to post a detail photo of their 2-cylinder fuel pump, which shows how the cold start thermostat housing fits?  I took the top of the housing off to check the movement of the thermostat and now i cannot get to fit back tightly.  I am attaching a photo of how mine fits now for reference and want to confirm if this is the correct fit.  There was no gasket between the top and the bottom, and now it looks as if water could leak between the 2 metal surfaces.

thanks.

Hans

[ja17]

The housing does don't clamp down all the way. It is a compression fit and a gap is normal. If it does not leak, its fine.

[wwheeler]

My 220 SE Ponton injection pump (ZEA) has a phenolic spacer between the housing and the pump body. It is sort of oval shaped with flat edges and about 3/16" thick. I didn't see that on yours and then looked around at other 220SE Fintail pumps (ZEB) on the internet. The ones I could find did NOT have the same spacer I have. So maybe the Pontons had it and the Finatils didn't. The pumps did have some significant differences but were both basically similar two plunger style pumps. You could call an injection pump rebuilder and they would know for sure.

Joe is correct (as usual) that the thermostats seal to the housing by compression. You can add a thin layer of sealer for insurance, but you shouldn't need it. And yes, there should be a small gap between the housing and the pump body. 

[hansr433]

Joe and Wallace - thanks for your replies.  As you can probably tell, my experience working on a W111 is extremely limited.  I am better with vintage BMW bikes.

Here is what my housing looks like, open.  Do you see any issues I should address before putting it all together?  BTW, how is the thermostat removed if one wants to test it?

Hans

[wwheeler]

The thermostat bulb is in the housing that has the coolant lines going in and out. It should come out with no force, but may be corroded in. The thermostat is brass and the housing is steel BTW. Do you have your coolant drained at the moment? If not, you will get a rush of coolant coming out the housing when the bulb comes out. Drain it first.

Also while there, check the small hex head screw to the left. It has an offset pin that when rotated, will lower the mechanism and effectively disarm the WRD operation. You would do this if the thermostat bulb is stuck in the cold position. Make sure the offset pin it is not in the position where it is pushing the piston down.

Do you know that your thermostat bulb is working?

[ja17]

It doesn't hurt to add a drop or two of thin oil on that sliding piston while you have it open.

[hansr433]

The thermostat bulb is in the housing that has the coolant lines going in and out. It should come out with no force, but may be corroded in. The thermostat is brass and the housing is steel BTW. Do you have your coolant drained at the moment? If not, you will get a rush of coolant coming out the housing when the bulb comes out. Drain it first.

Also while there, check the small hex head screw to the left. It has an offset pin that when rotated, will lower the mechanism and effectively disarm the WRD operation. You would do this if the thermostat bulb is stuck in the cold position. Make sure the offset pin it is not in the position where it is pushing the piston down.

Do you know that your thermostat bulb is working?

Wallace, I am about to check.  The motor is full of coolant and I would hate to drain it.  Is it safe to clamp the 2 coolant lines with a Vicegrip or similar to avoid the coolant rush, or will this destroy the hoses? 

Which hex screw are you referring to? 

I made little video of moving the plunger (?).  The movement seems firm but smooth.
https://www.dropbox.com/s/4789zv3c7rk763q/MB%20220SE%20Cold%20Start%20Plunger.mov?dl=0

[hansr433]

Great advice.  I have some 3-in-1 oil, or should I just use clean motor oil?

Hans

[ja17]

Your 3 in 1 is fine, auto transmission fluid, a thin synthetic motor oil  etc.

[wwheeler]

You don't have to take thermostat out if you don't want to. I thought you mentioned that you did. Yes, hose clamps pliers will help some. Having coolant drain out is a problem in that you don't want it getting into the pump and all over the plunger below. Other that, it is just a small mess.

The head of the screw with offset pin is between the WRD housing and the red "OEL" cap. If you can push your plunger down a bit, that screw is probably not set in the disarm position and I wouldn't worry about it.     

[mrfatboy]

Is it safe to clamp the 2 coolant lines with a Vicegrip or similar to avoid the coolant rush, or will this destroy the hoses? 

You can cover the vice grip jaws with two sockets. This  will provide a smooth surface when clamping the hoses. Or you can buy a specific tool that does the same job.

[hansr433]

Thank you for your answers.  I have circled the bolt in red what I think Wallace is talking about, but not moved it yet.  Is that the bolt used for locking the plunger? Also, the brass plate has a cutout circled in red.  If this plate were turned clockwise a bit until it reaches the small pin, then the plunger assembly would probably rise since it is spring loaded.  It is currently in the correct working position?

I started another thread "M127.984" with some videos of me testing the thermostat and the engine hunting and will continue to post there.  If one of you has some thoughts on why the engine is behaving like this, please let me know.

[wwheeler]

Yes, that is the bolt I am talking about. My understanding is that you press the bolt in and then rotate the bolt to the right 90*. The pin is offset and will move the plunger down far enough so the pump is locked in full warm mode. If the pin is in the upper position then it allows the thermostat to act on it. This is described in the workshop manual for Passenger cars starting 1959. It is on page 07-10/12. The bolt is #59 in that illustration. 

I have never completely torn my WRD down on this this car like I have the later 280SE. So I am not as familiar with the internals. Not sure I am aware of the notch in the brass piece.

[PeterPortugal]

Hans,

For the record I have adjusted the linkages and came up with 237/238 mm centre to centre on the fuel injection pump rod.

Regards

Peter

[PeterPortugal]

To make this clear to casual readers, this is for a 1963 W111 with the two plunger injection pump. Not a W113.