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 !!!