I suspect there's more MFI experience here than on Pelican's Mercedes board, so here we go... Yes, I'm looking at you, Jonny, and all your friends in the middle of your long, dark, cold winter! Fun fact: At the winter solstice last week, 8 hours and 9 minutes separated sunrise from sunset here.
1971 280SE with a 250SE motor in it. Bosch 6-plunger MFI pump much like on 911s of the time except the pump cylinders are inline rather than in two rows like the 911 pump. Other than that the tech is extremely similar.
I have no history of the pump other than it has been installed in this non-running car for about ten years. With much patience, the car will start, and will run OK (but prouce little to no power) until warmed up. Then it dies. I've been through all the adjustment and tuning. The MFI pump is what's left to investigate.
I have the pump out and have opened it up. I don't know enough to know what I am seeing, but what I'm seeing seems strange to me. I'm ignorant, so that strangeness doesn't mean much.
On to the pictures:
The space cam and stylus, with throttle closed. Note the meaty part of the space cam off to the right of the stylus.
When the throttle is opened, the space cam turns clockwise, and the meaty part of the space cam moves
away from the stylus. The stylus moves across an essentially flat part of the space cam, and the rack moves only a faint twitch. Is that right?
As I understand it, the rack should turn the black collars at the top of each cylinder to change the amount of fuel that goes to the injector. From full throttle to no throttle, the collars don't turn more than about two hairs breadths. Note also that cylinder number 2 gets no fuel- it seems like the spring does not push the cylinder back down. I can move it with my fingers, but it doesn't move on its own.
The regulator end, with adjustment screws. Moving the centrifugal weights does exert spring pressure on the front of the space cam. but does not move the rack or the space cam.
Little known fact:Bosch makes black boxes in silver. See immediately below. Atmospheric pressure can on the right, (removed) temperature sensor on the left. These bars and linkages and springs and ladders do something. I think.
I think I read that you are supposed to be able to move the rack by threading a 4mm bolt into the end of the rack and moving it. This one is locked up tight.
This is clearly beyond me, and will likely be going off to the MFI pump day care as soon as I can locate a trustworthy one that doesn't require arms and legs in payment. I'm open to advice and suggestions and help.
Teach me. Please.