Warm starting

[reggie]

Any tips to improve warm starting - ive trawled through the technical site but  Car fires up straight away when cold - but spins over a few times when hot, I give it a bit of gas and it coughs into life, it puffs a bit of smoke out and settles down ok, Its not blue oil smoke - more greyish. 
Reg

[Ulf]

Mine does almost the same, fires up when warm, but only on 5 cylinders - then a blip of the throttle and everything is fine. For me, it's just a minor annoyance that I've gotten used to over the years :-)

[kayemoxon]

On reading the manual carefully when I first bought my 67 250sl I discovered the correct procedure Mercedes recommend is (from memory and it works for me!)

Cold Starting- Insert key and allow 10-20 seconds to prime the system with fuel. Turn ignition key but do not apply any throttle. Engine should start a little rough for a second or two and settle down to a fast idle around 1100rpm which will settle to normal idle speed as engine temperature rises.

Warm starting:
Turn ignition key whilst applying a little throttle gradually increasing throttle as starter spins. Engine should start and settle to normal idle

Hot starting:
Mine starts without applying any throttle

Any cold starting problems would indicate possible issues with the cold start valve- plenty of advice on the forum
Regards to all
Kaye  (Cardiff, South Wales, UK)

[reggie]

Mmmm-strange-I think i will try turning ignition on and waiting 10 seconds before i start it when its warm-just to see if it is fuel evaporation-car still in paint shop-its in colour now-just bonnet (hood) and boot (trunk) lid to polish up, as of today, then build it back up, ive realy missed not going into garage to faff about with it 
Reg

[aeescobar]

The warm or hot start is an on-going issue for me.  In the past, I would let go of the ignition key after a second or two of cranking if the engine doesn't start and then repeat this process again and again until the car finally started up.  Now what I do is to keep the engine turning longer than normal, sometimes up to 10 seconds, at which point the engine finally starts.  This seems to work pretty consistently.

[Witt]

I may have solved my hot start problem, never was a real problem just a delayed action, by chance.
( Purists please stop reading the rest of this post.....)
Waiting to replace a faulty thermo time switch, I rigged up an underdash button that would trigger the cold start relay only during starter cranking. Now I can use that setup to activate the coldstart valve during hot start.
I have replaced the TTS but left the button in place just for that reason.

Come to think of, I know for a fact that the early fuel injected VW's Golf / Jetta  used the cold start system to improve hot starting. So, I did not stumble on something entirely new.

CHEERS !
WITT !

[reggie]

Hi Witt
Where is the TTS 

[Jonny B]

The thermo time switch is in a small pod on the left side of the engine, by the 2 and 3 spark plugs, in later cars it is screwed right into the block. See the tech manual for a great amount of detail about the switch and how it functions.

[Witt]

Hi Reg,
The TTS is located on the cylinderhead to the right of Number six sparkplug on my 1970 280SL.
I strongly recommend that you check the technical forum on this site which will give you excellent description of the whole cold start system.
 

CHEERS !
WITT !

[ja17]

Checking cold starting aids is fairly simple. When the engine is cold, both the intake valve and the injection pump solenoid (if your pump has one.....it is the top one if you have two) should activate (use a trest light or meter). If the CSV does not activate, hook a ground to the large screw on the thermo time switch and try starting again. If the CSV now works you have a bad thermo time switch. If it still does not work then you most likely have a mal functioning relay.  Cleaning the contacts in the relay usually fixes this problem.

Good starting W113s  will normally start imediately hot or cold by just reaching in to the car and turning the switch.