soot on injector +FPR ?

[Da Tow'd]

Howdy Gang,
Still trying to figure out why No start on a '90 735IL
When we pulled the plugs to do a compression test (all 175psi)they were wet and black.
The last time the engine ran the exhaust manifold got red hot

We pulled the injectors to see the spray pattern -they all spray good
no leaks
we were wondering about all the soot on the injector
why would there be soot on the injector as they are before the intake valve and not in the combustion chamber.
all 6 look like this -275kKm on motor

We are trying to figure out the fuel rail
does the fuel come from the pump to the Fuel Pressure Regulator?
or does the fuel go to the rear end of the fuel rail?
does the vacuum line have to be hooked up to the FPR to test?

thanks
hank

[shogun]

Hank, you can see the routing of the fuel hoses in the ETK here
http://bmwfans.info/original/E32/Lim/735i-M30/USA/L/A/1990/01/mg-13/
and here
http://bmwfans.info/original/E32/Lim/735i-M30/USA/L/A/1990/01/mg-16/
a bir of crud is normal after that mileage. You can clean them or buy new filters etc from here,
http://stores.ebay.com/Mr-Injector
The fuel regulator valve has a diaphragm inside, that sometimes breaks too.


does the vacuum line have to be hooked up to the FPR to test?

I think so, see the regulation o the fuel pressure valve

[Da Tow'd]

Shogun thanks for all the helpful sites
we installed new injector O rings and put it back together

We drilled 2 -19mm holes in the exhaust pipes (ahead of the cat) to see if the engine would run (thinking that the cat was plugged.

new plugs and it started but
would not run at idle and would back fire thru intake every once in a while.
no power no revs
we ran it for 10 minutes---with many starts- I felt sorry for the flywheel ring gear

After the 10 minutes of running poorly we looked at the cat and shield and they were glowing.

The vacuum gauge hooked up to a tee at the vacuum hose on the FPR and it said late ignition timing

we checked the vibration damper/timing wheel and found that it would spin free on the crank
must be a woodruf key sheared.
tomorrow we will tear into the front pulleys and timing wheel annd see if the hub key is shot.

Still waiting for the Bentley manual
thanks for the spiritual guidance
hank

[Da Tow'd]

Just a note of thanks for the help
we replaced the sheared woodruff key and bolted it backtogether and everything runs and sounds good
Sort of disapointed with the Bentley manual as there isn't any engine section other than
removing and replacing. OK there is valve info but it would have been neat to see the lower end
We did find all the torque specs we needed

thanks again for all the help
hank

[shogun]

Thanks, Hank

nice feedback, the board lives from feedbacks. :)