The Org - Serving W116 Enthusiasts for over 20 years!

Main Menu

280 SE problem ignition

Started by KASTE, 15 March 2023, 09:42 AM


Good morning everyone
I have seen all the posts but I have not found anyone who has had the same problem as me or the same symptoms or maybe I may have missed it and I apologize.
I have a 280se from 1978 and it has the following problems. I try to be as concise as possible:
I turn on the cold car, it starts immediately, it accelerates and decelerates by itself for 1 minute, as soon as it warms up it goes to the right idle, at 80 degrees I set off and after 4\5 km or 5 minutes on the road when I accelerate the car has gaps and it starts to run on 5 cylinders\4 cylinders, I stop, turn off the car and immediately turn it on again and everything works perfectly again but after another 4\5 km or 5 minutes it starts again with this problem.
if I leave the hot car turned off for more than 20 minutes (still a little hot) after that it doesn't restart immediately and the motor turns many times before it turns on again from hot.
I leave it at 80 degrees and a constant oil pressure of 2.5 bar after 10 minutes cylinder 6 no longer works and then 5, 4 and 3 until the engine stays on with only 2 cylinders and then shuts down completely .
I beg you, help me understand what the problem could be because when the car is fine, everything runs like a god without problems but when he plays that joke on me, I can't drive it anymore, risking accidents.
thanks to all and to whoever can help me


VISTA MOTORE (2) - Copia.jpeg




Could be a blockage in the fuel system? When the car is stopped the dirt/blockage drops to the bottom of the tank, the when driving it clogs the fuel line again???
1975 280S - Australian delivered


è rimasta ferma per 2 anni ma quando l'ho comprata e ho fatto 200km per portarla a casa non mi ha dato problemi, dopo con il tempo ha cominciato a fare questo scherzo fin che ora è diventato insopportabile


My first thought is plugged fuel filter. There is one in bottom of gas tank and the other by the fuel pump.

The surging during warm up could be the WUR.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'21 E450 Cabrio


ok grazie ho preso la pompa nuova per sicurezza ma il wur dove si trova di preciso?


Ciao Lorenzo,

qui si parla inglese. Alcuni di noi forse possono parlare e capire italiano, ma lo majorit√† no  ;)

    Saluti    Bernd

1976 Merc 6.9   Magnetit blue


I'm sorry I copied the wrong translation believing that the pc had already translated my fault thanks for telling me


I'll answer Lorenzo's question in English.  Unfortunately the WUR is located in a really terrible place on this car (ask me how I know).  It's on the side of the engine under the intake manifold.  If you don't have access to a lift, you can see it if you lie down under the car and look up behind the oil filter.  The WUR is the thing with 2 fuel lines, a vacuum hose and an electrical wire connected to it.

1977 280SE
1983 300D (sold)
1988 BMW 535is
1999 E320T (sold)
2009 E350T (wife's)


good morning everyone, I'm happy to tell you that the problem was the fuel pump that didn't work so well anymore, replaced, the machine is back to working perfectly!!!!