Quick qestions on the W124 model

[Donbronski]

I have a 88' W124 2L with the stromberg carb.

Starts without fail all the time everytime (knock on wood) from cold it'll only want to idle @ 500rpm unless i engage the choke manually by raising the rpm then it will hold at about 1100rpm increasing as the engine warms up... is this normal so far??

If i don't engage the choke it will idle rough & will eventually cut out after about 5mins

Also (when engaged) my choke will stop working at about 40*c allowing my idle to drop back down to a very lumpy 500rpm. Only at 80*c or above the car idle nicely.

My questions are
:- Is my choke supposed to increase as the engine warms up?

:- Is my choke cutting out too ealry?

:- Why does the engine only idle @ 750rpm when @ 80*c?

Please shed some light... thnaks

 

[imadoofus]

Warm idle speed of 750 is normal. At least it was in my 320.

 

[jaymanek]

When you say engage the choke, you mean by flicking the accelerator pedal?

If so then this is normal.. on my W123, I get in, flick the pedal then turn the key... this action sets the choke to where it needs to be.

The choke has 3 teeth on it... moves down one once engine starts to warm and then at around 50-60 it should go down another tooth so that fuel enrichment and rpm drop.. Its a very fine art to adjust the choke up properly and takes days to set as you can only readjust when the car is cold again.

Sounds like the teeth on your choke are just slightly worn and maybe skipping a tooth or maybe just that it needs some adjustment so it stays on a bit longer.

Great fun and games these old carb models.

 

[Donbronski]

Not sure i have teeth on my carb think i might have a bimetalic strip. It's a little tricky fiddling with as the choke arrangment is on the underside of the carb & pretty much hard up against the bulkhead. I might try having a look with a mirror, ideally i don't wont to remove it.

It's so annoying that it wont just idle on its own!

Do you think pictures would help?? i have got a slick 13mp kodak camara.. well my brother has.. hehehe

 

[jaymanek]

Hmm im pretty sure you will have the same Stromberg carb which has the choke on the side.. On the underside is the fuel cut off solenoid..

The bi metallic trip just tells the choke what temperature the coolant is at and accordingliy this moves the toothed lever.

Pics might help.

 

[Donbronski]

Carburettor Pix

Ok, here is my carb. Does it look familiar?

If the teeth are worn & nead replacing, do you know where i can purchess a carb kit from?

I have been reading through some of the old threads on carbs, your name popped up a few times, you've had trouble in the past yes? I like in one of your threads you mention that your mate has an old mercedes engine in his garden just sitting catching dust.... I need mates like this!