W123 idle problem

[whitechameleon]

Hi Guys,

My W123 280E is having idling issues, it was just about ok in the winter months but now as the weather warms up the car runns a little hotter and therefore once warm it idles a little slower and now seems to stall now and again.

Can anyone tell me where the idle screw is so i can speed her up a little.

She's a 1984 280E

I've done a few searches on the web and found a few things but the screw doesnt seem to be where it says.

Thanks in advance.

 

[esox]

Be aware that there may be another issue related to your poor idling,and simply raising the tickover will possibly cure the problem but just mask the real cause.
But,i think i would do the same to start with so if you want to find the idle speed screw have a look at this pic.
This is the 4-cyl 230 engine but i think it uses the same K-Jetronic mechanical system as your 280(or is it L-jet,can never remember) and will give you an idea of what to look for.
The speed screw is on the throttle by-pass circuit - look for the tubes that run around the throttle body,through the cold-start valve.
The screw on my 230 pic is on the inlet side,above/between the middle two inlet rocker arms,slightly to the left - the largish,slotted screw.See it?
A small "clue" to its location on my car is a cut-out in the air filter housing to fasillitate facillitsa facilsita make it easy to get a screwdriver on it....

 

[Dieselman]

I would say it sounds like you might have an air leak into the inlet manifold. Check the vacuum or spray plus gas around all the pipes and joints. If there is a leak the idle will alter as the oil is drawn into the manifold.

Also try some injector cleaner to clean out the fuel system.

 

[whitechameleon]

Hi mate,

Thanks for the advice. Have had a look but cant seem to see the screw anywhere.

I've taken some pics as i think i may have a different system.





Thanks guys.

 

[Ian B Walker]

I think your adjustment is made from the threaded bar on the linkage on the left of your posted picture.

 

[ddentrec]

Here is the idle screw - this is viewed from the front of the engine.

Just rebuilt my M110....no time to put it back into the car....make a good table though.

Do not forget about your cold start valve and warm-up regulator: if the regulator is faulty then the hot/cold idling can be rough. It is located on inlet manifold side, below the manifold itself (just follow the fuel pipes that disappear under the manfold). Not easy to access either.

 

[andy_k]

I'll post a pic tomorrow afternoon - but there is a big (white) screw below the injection unit that controls the tickover on our 280.

If my memory serves me correctly, it's just about in line with the number 2 spark plug

edited because ddentrec posted a picture after I'd described the screw

that's the one I was referring to - ok it's in line with number 1 plug

Andy

 

[whitechameleon]

Thanks guys, found it and done the trick for now.

Checked all breathers and seem fine.

Potentially duff warm up regulator though as seems to be running very rich.

 

[Dieselman]

I'm sure the tall post with teh hole down next to the fuel distributor is the mixture screw.

 

[Ian B Walker]

I'm sure the tall post with teh hole down next to the fuel distributor is the mixture screw.

it is, thanks for pointing it out.

Note if your car has a cat it does not have this.