Replacement of the IP Diaphragm

[Fisherman]

Anyone ever replace the IP diaphragm in a pneumatic governor?
I'm looking at attempting this feat if someone can tell me that they have done it and it was successful.
I can find no info on this procedure so without some kind guidance by one of the fellow posters I think this may be too much for me to deal with.
Supposedly this diapragm is shimmed to make the initial adjustment for altitude and then via the manifold vacuum on the pneumatic governor it adjusts for altitude as it changes. I am now certain that this adjustment is off on my IP but don't want to do the "Murphy" thing and break something that is currently functioning (just not well).
Thanks

[psfred]

I'd not try -- not only is it somewhat difficult to get the shims correct (there is a procedure in the old Chilton's manual, 68-73 MB), but you MUST get it properly installed or the governor will run away when you start it, blowing up the engine unless you manage to get out and get the injector lines off before the rods go -- it falls open to full throttle and the shutoff valve doesn't work since it is no longer attached. Not for the faint of heart, especially if it is not adjusted correctly now.

What you can do is loosen the bolts holding it on and check for oil in the vacuum side and fuel in the pump side -- if you have fuel in there, drain it all out and replace the 0-rings on the pressure valve holders, they are leaking. Oil if from excessive blowby or a bad blowby valve on the intake manifold. Liquid in the system causes it to act funny -- no power or hard starts.

Check for leaks in the hose and diaphram, too -- hose leaks can be fixed, but if the diaphram is leaking, it must be replaced.

Peter

[Fisherman]

Thanks Fred.
I am having a really tough time with this decision as I'm 99% certain that this is what is causing my excessive smke here at home. If I travel down to sea level the car does not smoke but for a slight trail when you have the pedal mashed to the firewall.

Oh well, I guess some things we just learn to live with. Maybe I'll try the guy listed on that BMW site to see if he could do the job for a decent cost. My local guy will charge me more than my car cost to do this project.

[psfred]

Fisherman:

There is not one thing wrong with your IP. Do not mess about with it!

What you need to do is reduce the max fuel delivery at high altitude or put up with the smoke!

I'm not sure where the adjustment is (on the pump, I think, a screw with a lock nut) -- this determines the maximum travel of the fuel delivery control rack. You are overfueling at high altitude because the air is less dense, not because there is anything wrong with the pump. You will get lower power at sea level, but that may be preferable to huge clouds of inky smoke!

Peter