Keeps Stalling - Cold Running Problem

[normany]

I have a 1984 280E Auto, it has been running fine, but has started to stallout when it is cold.  It may run for a while then stop, it will generally restart OK but may stall again.  When the engine reaches 80 degs, it runs fine with no more problems.  Is there some type of thermal switch which may be playing up?

 

[Andy]

Keeps Stalling

Hi Norman.

Your 280 stalling, first things first. Is the engine tune spot on. (By the way how many miles has the vehicle covered). Make sure the tune and emmissions are ok. Even though the problem is with it cold. Does the car feel like its got a flat spot when cold? There could be a number of faults with a car of this age.

1. Warm up regulator, is operating correctly, are the connections good, & not rotted away.

2. Is the cold start air slide working & opening properly. Even a slight difference will cause the engine to idle slowly when cold. (If the cold start valve is a problem, take a good long look at it before you attempt to replace it. Not for the faint hearted, when you look at it you will see what I mean)

3. Are all the breathers unblocked. Take nothing for granted! If the breathing sytem is not in good order free from sludge & grime. More problems.

4. Does the vehicle use oil? Its almost certain to. Valve stem oil seal problems as a rule. Noticable more on a run. (For the rest of you with 280 engines (110), lack of oil is the most common reason for these engines to fail) You will take your vehicle down the motorway, thinking MY ENGINE dosn't use oil, then the next thing you notice is a noise. If you first don't realise you've lost oil pressure. By then its usually to late. Take my advice. Check your oil before you leave on a long journey. Especially if it is a  long motorway journey. And again before you start back. Ignore at your peril!!!

Any way back to business, if the engine isw coked up. By that I mean the valves. Excessive coke build up on these engines will cause cold start running problems.

Why I hear you say? The fuel mixture soaks into the coke instead of being burnt. Causing a weak mixture hence a slower tick over.

Hope I been of some help.

Regards
Andy @www.mercedesservicing.com