New W123 owner. That's not strictly true . . . .

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Jun 2, 2023
1983 W123
I am an old owner of a ?1983 W123 2 litre petrol - I suppose it has to be petrol, no one was making 2 litre diesels then, even the london taxi was 2.2.
I have had lots and lots of 'old' Mercedes, usually W124s I bought cheap from round the back of the Mercedes dealer on the Isle of Man so I know a few things about them such as how well made they are and so on. Also I know that you do not need to buy a new fuel pump relay for petrol 124s, the fault is that Bosch can't be bothered to make them properly. When yours stops running suddenly, it is probably the fuel pump relay behind the starter battery. Just remove the relay, prise its cover off and you will see cracks in the printed circuit where the actual relay contacts are supposed to be soldered on to the pcb. Just re-solder them and off you go happily never to repeat the sudden engine cut out.
There, did you all know that already or have I learned you sumthing?

Until recently I had a V70 Volvo and when the third thousand pound bill loomed for false fault diagnosis by incomptent garages loomed its ugly head I dumped it and said to myself I am going to get a car with No Computers. Hip hip hooray. This W123 has no electric windows operated by computer, a sunroof not operated by a computer, lights and wipers which work off switches - in fact about the only electronics that Faraday would not understand are . . . .eh . . . . nothing.

Anyway until today it ran like a dream. I think I need a new ignition coil to replace the original-looking one. It hasn't even done 200,000 miles yet. Nearly, at 195,872 but you would expect a coil to run for a full 40 years and 200,000 miles before packing up wouldn't you? You wouldn't? Oh dear.
I am trying to find out if it has a ballast resistor in series with the IGN supply to the coil, before I buy a new coil. Do they all have a ballast resistor, or did some have and some not have the resistor?
I'm pretty sure that in 1983, the car would still have a pair of ballast resistors. Look on the inner wing, near the ignition unit. They did make W123 200D, but many people preferred the power of the 240D which was the muscle car of the bunch
hi Alabbasi, mine doesn't have any ballast resistors . . . .
Anyway I think I may have found the fault, the co-ax cable from the distributor pickup was rubbing on a chassis rail - although I can't be certain, if that had rubbed through the insulation and earthed the screen of the co-ax, it would cause the fault. So I have cable tied it away from the chassis rail.
Hello gassygassy what were your running issues ? mine was running fine but now seems keen to stall after travelling for 15 mins. Not the fuel as it only get 98oct . bought a "newer" modern coil didn't fit the leads.
Hi all. Fault found . . . . after breaking down TWICE on the motorway, once only just made it from lane 2 to the hard shoulder when a nice policeman came along very quickly and towed me to a safe place.
Having changed the ignition coil which it wasn't,it turned out to be the 'new' fuel pump which had been wrongly assembled. A rubber gasket inside it had been fitted incorrectly and sometimes the pump worked and sometimes it didn't,
New fuel pump fitted and it goes just fine.

Only trouble now is that rain doesn't run away from the sun roof - I heard somewhere that is a difficult job. I'll have to youtube it.
. . . and of course the central locking doesn't work.
Hiya! I have no insights to your problems, but hello fellow 123 owners ;)

Mines currently in for a carb refurb, I miss it dearly.
My s124 E300D's only "computer" was the "digital" outside temperature displayb:)
This 1994 car could get 45mpg at 55mph on the motorway (brim-brim tank calculation).
Now I have a s205 C200 which the computer has told me I had got 60mpg+ under similar motorway conditions.
I am now searching for an s123 40+ year old estate.

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