Offtopic, Starting problems with my W123 250

[Des]

Guys,

I would appreciate your thoughts on this, on my 1980 W123 250

My 250 seems hard to start, it turns over over over fine, like it is turning over quickly enough, but it won't fire for say 15-20 seconds, I don't let it turn over over over too much without stopping, eventually it fires up and then proceeds to idle away fine,

if you were to stop the car and then switch it back on again it would fire up fine, it is only if it is left for more than a few days that it is hard to start.

So if I started it up today, started it tomorrow it would start fine.

I don't believe it is fuel/carby related as pumping the pedal a few times before starting and/or pumping it while starting doesn't seem to have any noticeable affect.

I don't believe it is the battery, as it turns over quick enough, i.e. it doesn't sound like the battery is dead or flat, you know that sound, where the motor isn't turning over fast enough.


I am wondering if it is something in the ignition? I don't know what though, coil? condenser? etc..?
I understand the W123 250 has electronic ignition, but that's about all I know about it


Thoughts?
comments?

 

[B13]

Which carby do those have, and do they have a manual or automatic choke?

I'd say it sounds like a combination of petrol evaporating from the carby float bowl and the choke not coming on early enough or closing the primary barrels completely...

Ian.

 

[Andrew280SEL]

Interesting...the odd thing is, it sounds like what my 280SEL sometimes does when one of the injectors leaks (presumably) and makes hot starting hard.

Except yours is a carby...?

However, I also had a bad coil lead once which caused a similar effect (sort of). Have you got any spare coils/leads laying around that you could test just to be sure?

 

[Des]

Which carby do those have,

As stupid as it sounds, I don't know sorry, had a look in the Haynes manual that came with the car and it tells you everything but what you actually want to know...i.e how to remove the engine, but not what type of carby it is.

and do they have a manual or automatic choke?.

Automatic choke yes

I'd say it sounds like a combination of petrol evaporating from the carby float bowl and the choke not coming on early enough or closing the primary barrels completely...

Ian.

Ok!, when I got the car it was running quite rich, I don't remember what it started like though, my mechanic has fixing the black smoke coming out the back and the rich running, maybe something he needs to look at again.

I have had a lot of problems in the past with our other carby benz, a 230

should the carby be rebuilt? I know that does not cost a lot to do.

 

[Des]

Interesting...the odd thing is, it sounds like what my 280SEL sometimes does when one of the injectors leaks (presumably) and makes hot starting hard.

Except yours is a carby...?

Yep carby model,

However, I also had a bad coil lead once which caused a similar effect (sort of). Have you got any spare coils/leads laying around that you could test just to be sure?

Yep could do that, replaced the coil on our other benz a month or so ago with a new one,

 

[Des]

I had a look in the owners handbook and that also fails to mention the type of carby on these cars.

 

[Andrew280SEL]

That's a pity.

I had a look on the internet, and perhaps my Googling skills just suck , but I couldn't find anything.

Is it possible it has the same Solex carb as the 280S?

I'll keep looking, but maybe someone knows exactly what it would have.

 

[Des]

I don't know mate, my 230 has a Zenith carb,

I understand the motor is basically carried over from the W114/5 range but they added electronic ignition


I must have been one of the South African chaps on the w116 website that mentioned these carbs can be problematic so I'll get my mechanic to give it a rebuild and see how that goes.....

Also getting a new radiator and thermostat fitted next week

 

[Andrew280SEL]

Ah ok.

Well this might not be exact groundbreaking proof or anything, but this forum topic would suggest the 250 would have the Solex 4A1 carb:

http://forum.mercedes-benz-clubs.co...ghlight=&sid=775f1bd49472d7f5463eb5c6bac66d16

 

[Des]

Hi Andrew and others,

yes found out today it is a solex carb, had a new radiator and thermostat fitted to my 250, had dramas with the new thermostat but anyway....

yes Solax carby
ordered apparently the last remaining genuine MB rebuild kit in existance for it, $270.
That in itself seems odd, that it would be the last kit for these carbies.

My mechanic has had a look at it and said he can see fuel escaping from the carby and a rebuild should sort this out.

I've heard somewhere that carbies of this period can warp the body of the carby and this causes the leak.

So yes should be sorted soon.

 

[Andrew280SEL]

That's good to hear Des

 

[Nütz]

Solex 41A can also be found on BMW E21 and E24's

If this helps any http://e21.tricord.be/e21/projects/solex-rebuild.php

And also Solex 41A

 

[Des]

From what I've read the 280s W116 also uses the same Solex Carb

for anyone interested this is what the bag of parts looks like to rebuild it

 

[Nütz]

Have you entertained a Weber 38DGAS ( Weber Part # 18930.032)as a replacement over that infamous Solex?

 

[Des]

Have you entertained a Weber 38DGAS ( Weber Part # 18930.032)as a replacement over that infamous Solex?

No, I think it would ruin the originality of my car

I want to keep my car original and pure.

Everyone I talk to about these keeps telling me replace it with a webber, I just don't understand, I mean these were the best cars in the world at the time and should run as such.