Mercedes 380SEC 1976/1985 Model

[Martin Haywood]

Have a problem with the car not firing, has spark and fuel pressure at the injectors. I have found lots! of petrol in the oil, about 12 litres mixed.
Replaced oil with new. The diagnostic plug is the old 9 pin one (round)
The air flow shutter is not moving on cranking? I have to find, if this is due to no vacuum. Of course it might be relevant to take out the plugs and wind the engine to build up oil pressure. As the petrol in the sump might have washed the bores and have no compression. Cranks quite slowly, but I am told this is normal on this type of engine. No hint of it firing.
Any ideas? would be most welcome how to diagnose via the 9 pin without a scanner/reader? I have an LED tool and one of the wires to the CU has a code wire. Just have to find which colour...... NZ is fine.

[Idle]

You should repost this in the tech section, but I would recommend a compression test. It sounds like you have a scored cylinder wall; perhaps more than one.

[Jim B.]

The 380SEC was ONLY produced for the 1982-1985 model years.

It was introduced at the IAAA in September 1981 in Frankfurt for its "weltpremiere":



For the 1986 model year it was supplanted by the 420SEC.

Your question here needs to be moved to the Tech Section or better yet to :THIS busy tech forum for the w126 exclusively:

W126 S,SE,SEC,SEL,SD,SDL Class - Mercedes-Benz Forum

[barry12345]

We had one here some time ago. They have problems that are well known so a gas users portion of the site is better than this diesel portion..

I opted for used electronic/electric components to repair. The usual suspects where pricy new we found.