Bosch D-jetronic schematics?

[Frank Mallory]

>
>Can anybody come up with a diagram for a d-jectronic brain used on a 72
>mercedes 280 sel 4.5? I just Inherited the thing and now that I own it, it's
>gotta run right. It's down to 4-6 cylinders and hopefully a friend who
>understands
>electronics has said he might help figuire it out. Yes I know it's brain dead.

I don't think you want to try modifying the circuitry in the brain box, or even
repairing it.

First thing is to check the plugs (not easy to get 'em out, but you'll get the
hang of it after a few times). Chances are, you will find several that are not
firing because they are fouled up. Put in new plugs and try to figure out while
they are fouling up. It could be due to a the cold start system, or possibly
because it is running too rich at idle or under load. The idle mixture can be
adjusted at the brain box, and the total mixture can be adjusted at the
pressure sensor (the grenade-shaped thing at the rear of the engine).

If the plugs are not fouled up, but on the contrary look like they are running
lean, it could be due to bad trigger points (bottom layer of the distributor)
or a bad throttle switch. Again, you can adjust it to run richer; but these
systems tend to go toward rich, not lean.

Bottom line: don't mess with the brain box until you have checked out
everything else.