940 emissions problems...

I have a '91 940 2ltr non-turbo Auto.
I have pulled my hair out this last few weeks trying to solve a rough idle
and slow pickup, together with intermittent pinking and stalling in
traffic.
It seems ( feels ) like a slight misfire on idle, yet it drives almost
perfectly. I have replaced Plugs, leads, rotor & cap, Fuel filter, air
filter and oil filter. I have checked the throttle switch and linkage, and
thoroughly cleaned the throttle intake. I proved no leak on the air intake
from the air filter, and there are no noticable vacuum leaks I can see...
The timing appears to be about 30degrees out, and there is increased crank
case pressure - enough to blow a small amount of oil out the top of the
filler cap.
All I can think of now is something to do with the breathers or emission
control system - any thoughts anyone ??
Where to go from here, as I can't manually adjust the timing - or can I ??

Help !!!

 

slow pickup, together with intermittent pinking and stalling in

Check the fuel pressure regulator on the fuel rail for a perforated diaphragm.
Excess fuel gets sucked into the intake. Also check the attached vacuum hose
and the fitting it goes to for clogging.

The crank case pressure problem could be a clogged flame trap.



Had
79 245 D,
81 240 D,
86 240 320,000mi and running when traded
Have
94 944 White 144,000 The New one
94 944 Green 257,503 mi CRUNCH Parted out
94 944 Maroon 135,000 mi

 

Vrparts declared:

See my post re:
940 timing anomaly
13/11

Got it pinned down to a lug on the back of the bottom pulley sheared off,
putting the timing notch 90degrees out, although the timing is only really
slightly out....