Hi List, 

My 1.9 WBX is running rich. The motor runs fine but the plugs and exhaust system are covered with black soot. I have installed fresh plugs, I have checked the plug wiring, I installed a new Bosch green coil, I changed the temp2 sensor, there is a new Bosch cap and rotor. I put new vacuum connections to the fuel pressure regulator and the distributor as well as the other connections I could see. I have checked and cleaned the grounds from the battery to the transmission to the alternator to the coil and to the left head. The O2 sensor is showing about 1/2 a volt when idling and moves around when the speed of the engine is varied. If I cover the end of the exhaust pipe the engine will stall and the system holds the pressure so I am sure there are no exhaust leaks. I checked the timing and the mark on the pulley matches the middle of the case at idle (with the idle stabilizer bypassed). I have adjusted the air flow meter a couple of turns counter clockwise but it does not seem to make any difference. To make things more confusing every thing was OK last summer, the problem seemed to start when I changed the coolant last fall. 

Any suggestions? 

Thanks, 

George 

'85 Westfalia