Re: Black smoke arrives

["Scott Mo." <scottmo@teleport.com>]

Preston,

One possibility for the black smoke could be a poor connection to the
coolant temp sensor. If the ECU sees a high resistance, it may think the
engine is much colder than it really is and it will richen up the
mixture. The cold start valve will also operate briefly during initial
throttle application when the engine is very cold.  

You can go to my web page for details on checking this sensor.
http://www.teleport.com/~scottmo/ecusys.html

You should also check all of the crankcase breather hoses to see if any
have collapsed, as this could allow a buildup of pressure in the
crankcase.

Check out
http://www.teleport.com/~scottmo/vac.html
-- 
Scott Mo.
1989 200TQ
http://www.teleport.com/~scottmo