Hi
I'm the owner of a 404.1 UNIMOG with the 280se motor from a w116mercedes car. the motor with the fuel injection&double cam, yesengine no.:110985 1000012)
now there's been some modifications done to the inlet manifold to make it fit, and the injectors apparently are from a 450slc motor. i bought this from a friend of mine, a 4x4 mechanic, who said he'll finish the conversion for me.
now, at first the motor was starting, idling was ok, but it wouldn't pick up revs if throttle were opened. I had the fuel pump tested, and it delivers 5-8 bar of pressure which apparently is normal, so we cleaned all the injectors, after which it sounded better. it starts ok, picks up revs, but now the motor runs very unevenly. now all that's left seems to be the fuel distributor, and everyone i spoke to said NOT to open it.... and a new one is on the expensive side... my question is: can you give me info on these mechanical fuel distributors, how can we check/adjust it? (my mechanic mate's not into fuel injection systems...., he wants to put two SU carb's or a weber on) I'm keen on keeping the fuel injection system, since if it works, I reckon it will give better performance& fuel consumption. Afterall, a team of german dudes spent some good time sussing the system out, it works on a zillion mercs, and I don’t know of any double-overhead-cam 280 motor that ever had a carburettor-:would a carb even work?, if so, where does one put it ( besides the amount of space left in the enginebay after getting that motor into the mog....) to ensure all cylinders get equal amounts of fuel (and all that technical stuff the german dudes spend their time on...)
i'd appreciate some thoughts on carburettors vs fuel injection, and maybe some info/references on these fuel injection systems
Maybe a reference to someone in South Africa who could have a look at it for us?
Appreciated,
floris,
Gauteng, South Africa

Actually there were many M110 engines with A carburetor. A solex 4A1.

What a mess that was. I can't imagine replacing a fuel injection system with a carburetor.

That fuel system needs a constant fuel pressure, proper adjustment and even fuel flow on each cylinder. Mixture in your case can be done by ear. If you have misfires due to fuel it will be because of general mixture problems or specific flow irregularities. By cracking the fuel lines at the distributor (clean up leaked fuel with rags) one at a time each cylinders contribution can be viewed. Cylinders not firing will not be effected when they don't get fuel.

If you have one or two without change try swapping the injectors in those cylinders with ones that work. If the problem moves you have an injector problem. If it doesn't try moving the lines at the distributor. If the problem moves with the line a distributor is suspect. If the same cylinder is bad look for ignition of false air (vacuum leaks).

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician