W116.org

D-Jetronic was not simply a prototype and was widely used on European cars of the era such as Volvo and Mercedes-Benz, as was K-Jetronic. The system was well-sorted and very advanced at the time. I think the "Bosch specialists" simply couldn't be bothered.

It does sound like you could have some injectors stuck open...

Tim 

Thats what they told me, but i noticed too just now when i looked up som information on the system that it had been used on many more cars then just mercedes.

Porsche, VW, there's quite a few.  I'm still amazed the injection specialist wouldn't work on your car.    . They're lazy, it's not rocket science.  Whilst there is specific testing equipment for d-jet, any experienced shop will be able to use a scope, a multimeter and a vacuum gauge to test every component.  If injectors are the problem after all, any shop (even lazy ones)  should know how to test the spray pattern and quickly tell if an injector is stuck open.

If there is a Mercedes Club in Sweden or a Swedish Mercedes forum, I would approach them and ask for recommendations of what mechanic to visit.

First my steph dad is gonna check it, hes real good at almost everything that has to do with engines and cars. Even though he never touched a merc before in his whole life, hes done a lot of work on mine. Then if he cant find anything. I was think maybe if i change the oil, then fuel it up and use som injector cleaner. Or else i have to hire someone to do the work.

Here's a quick tip for checking the injectors before you do anything else.  Whilst the engine is running you should be able to hear each injector "clicking" as the solenoid operates the plunger and valve. 

Use a long screw driver placed on the injector like shown in the photo below and put your ear on the end of the screwdriver. (or you can use a mechanics stethescope if you have one). 
You should hear each injector clicking away at a regular pace.  If you can't hear an injector operating it could mean that the injector is stuck open but keep in mind it could also mean it may be resting at a closed position due to an electrical fault.

Thank you, i will try that but now its raining like the sky is falling down. Anyway today i changed the oil, fueled it up and put some injection cleaner in it. So now atleast it runs. But i will check that screwdriver thingy tonight if it stops raining

I couldnt try that with the screwdriver, because i have no idle and when someone is giving it gas it vibrates to much.  We made a test drive today, and its obvious that it gives to much fuel, its just black smoke coming out of the exhaust when youre driving. Tonight were going to remove all of the injectors and check them.

I tested my injectors by just take them out (easy) and sucking air backwards throug them at the same time as I gave it wery short pulses of current from a 5 volt battery. Don't apply a constant current because I'm afraid that they can get to hot.

Before you do this you could unplug them and measure the electrical resistance on the injectors whitout having to dismantle them.

/Niclas

Thank you niclas, that doesent sound too difficult =) By the way i was thinking if i could buy some "universial" injectors, but i dont get this with the cc? Should the injectors be the same cc as the engine or what? Please fill me in, haha

Today i checked the injectors, all of them worked perfectly! And then a bit later, this wierd guy came from nowhere, and asked if i had problems with the car, i told him yes and then told him what the problem was. He told me that his former boss had the same problem with his 450, and it was an easy problem, though it took him a very long time to figure it out. He didnt remember exactly but he thought it was a hose or something he replaced. And also he tipped me about this guy living pretty close to me, who helped his boss with the problem. So im going to see him this monday, maybe he can help! Or else im ready to start crying, hahaha

What about a burst pressure regulator diaphragm allowing fuel to be sucked in by vacuum?

and/or

Faulty temp sensors allowing max enrichment all the time.

Try removing the vacuum fitting off the pressure regulator and look/smell for fuel. You could also look down in the plenum chamber beneath the throttle housing for signs of excess fuel.

Tim

Now i checked almost everything possible, ive asked people who have worked with these cars their whole life, no one can come up with anything. But now i realised what the problem must be, the piston rings. Thats way to much work for me to do on my gravel driveway. I dont know anyone with a garage and i dont have the money to let a professional do it. Im hopeless, so i guess its time for my old benz to go to the graveyard.

bulba, that's no good.   Have you done a compression test yet?  I thought around 145psi is a minimum and 150-160 psi was normal but the library says 8.5bar or 123psi is normal.  Maybe that's for a low compression ratio engine.  Either way, it's worth checking the compression on all your cylinders before blaming the rings.  http://handbook.w116.org/Engine/107/M117_45/01-010.pdf

no i havent done that yet, im waiting for my friend to bring the tools. But i cant come up with any other reason. The only way for the gas to get to the oil is through the piston. But i will do a test to be real sure.

Okey now ive done a compression test, these are the results:

cylinder 1: 9 bar
cylinder 2: 10,7 bar
cylinder 3: 10,3 bar
cylinder 4: 17 bar (this one drenched the compression tester in fuel too)
cylinder 5: 11,4 bar
cylinder 6: 11,2 bar
cylinder 7: 11,1 bar
cylinder 8: 11,1 bar

So all of them are too high according to w116 handbook.