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D-Jet 280SE advice

Started by entresz, 22 February 2015, 12:49 AM

entresz

Hi all,

I'm considering purchasing a 1975 280SE with 177,000kms. The body is almost perfect, only minor rust under boot seals. It runs very well, the idle was so smooth I could hardly tell that the engine was running. It was absolutely fantastic to drive.
The 116 I had was a K-Jet 450- - - I found it to be generally reliable, although I did have to replace the fuel pump and injectors.
How does the D-Jet system compare to the K-Jet system in terms of reliability? I understand that parts are fairly expensive, and can be hard to get. I was trying to find injectors for a m110 D-Jet, and I couldn't find any anywhere. I did read that the injectors can be rebuilt however.

What do you reckon?
1975 Mercedes-Benz 280SE
1981 Mercedes-Benz 300D
Previous cars:
1979 Mercedes-Benz 450SE
1982 Mercedes-Benz 280E

marku

Don't know much about the K-jet but being mechanical I would guess it much easier to deal with. The D-jet is complicated but there is a lot of info available and Bosch have reprinted their  D-jet manual for the W116 which is worth having and gives a very clear explanation of its function. I would say that it is much more responsive and was around from 1968 on across VW, Porsche, Volvo and Jaguar as well of course Mercedes . Parts are available but very expensive from MB but there are other sources. I like the D-jet it is what a fuel injection system should be.
1974 450SE silver green/bamboo velour/green vinyl roof

mrkozzy

You are considering my very exact model.
Having spent a lot of time fixing things on my d-jet over the past 12 months, I can tell you they are a dream machine once you get them running right.
(Check out some of my posts if you want to know specifics)
There are certain  parts I found hard to get and I have been slowly finding and hoarding a spare or 2.
I have a spare dizzy, not real hard to get, but can be expensive, 2 x 2nd hand trigger points, some new ones around overseas but the asking price is $400+,
6 injectors pulled from a car at the wreckers last month, (altho I found a contact in Perth who has a bucket load of them 2nd hand at $60 - $80 each should you need any) , cold start injector, (hard to find a working one) and above all the computer.
This is the one that sits in the passenger side footwell. If this is faulty the car is never going anywhere. I picked up a working spare and later on found another which turned out to be a dud. (Altho these are fixable but you're looking at $400 to $550 to have it done professionally)
Most of these parts are 1st time replacement on my vehicle (except the trigger points, last done 15 years ago and I'm finding that as you fix or replace one it affects the workings of the next component along the line.
My best advice is to find yourself  a decent merc mechanic who knows these babys, and leave it with him for a day.
Let him give you the list of what needs replacing and in what order. It can save a lot of poking around in the dark!
I messed around for 6 months doing things the hard way. Changing things blindly because I was taking pot shots at problem solving.
MrKozzy

floyd111

I am about to replace/refurbish my D-Jet system for my 77 280SE. I want it spic and spec at any cost.
Until now, I found it hard even to find a parts list. I am well worried to get it worong, even WITH a manual (in case the 33gig ISO EPC is found to be openable)
Would you have the parts list for the D-Jet?

Also, I heard stories about improved-cheaper replacement parts for some of those related items.  Is that true, and if so, what are they? Are they worth it?
And yes, I am totally in over my head here. Financing, data gathering and parts sourcing will need to make up for an absolute 0 in experience I have in this area...

entresz

I've spent the last few weeks doing a fair bit of research on parts and have learned a bit about the D-Jet system in the process too. For example , I was having a hard time looking for the correct injectors. I found out that the Jaguar XJ12/ XJS use the same ones (the Green coloured D-Jet injectors). Searching for 'Mercedes 280SE fuel injectors Bosch D-Jet'' didn't bring up much, but once I found the part number I found I could bring up a fair few places that had the same part in stock, often for Jaguars, but they're the same actual injector.

I'm going to go ahead and buy the car- I don't suspect I"ll have many issues with it as it has been looked after extremely well. I have a mechanic friend that is a real expert on Mercedes, particularly the 116 and 123 models, so he should be able to steer me in the right direction if something should go wrong. It isn't going to be a daily driver, not like my 450SE was- this car is a bit too pristine for that application.

I've attached a photo of it (It's not a very good quality one unfortunately), but when I get the car in a few weeks I'll take some good ones.
1975 Mercedes-Benz 280SE
1981 Mercedes-Benz 300D
Previous cars:
1979 Mercedes-Benz 450SE
1982 Mercedes-Benz 280E

gf

Nice find! I can see a working sunroof too! Knew you'd be back! If you encounter problems with the D-Jet system be cautious of where and who you take it to in Hobart. You may be told all sorts of weird and wonderful Haynes manual Diagnoses! D-jet injectors can be flow tested and the pintels replaced if you need at minimal cost. I think mine were  about 100 dollars for all 6. They're tricky to access the bolts that hold the injector pairs.  Fuel pumps for D-jets I beleive are no longer available but You can just stick on a commodore one for cheap. Air slide valves are a common fault- expect 1000 bucks or more for a new one if you cant find a working second hand unit.