Hi, you might try the H2O temp sensor as this is one of the sensors that
tells the ECU to start heeding the O2 sensor (ie engine is warm) if this
happened when you changed fluid. It may be telling the ECU that the engine
is never warm, so it continues to run rich. Or, it may be the brain
itself... Hope not, Mark '87 hitop

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
George Thorburn
Sent: Monday, April 19, 2004 8:54 AM
To: vanagon@GERRY.VANAGON.COM
Subject: 1.9 running rich

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