Hi, I know that this post is a week old,but I'll give you two more
cents.When yu are rich when cold, your van computer is disconnected from
all the sensors-water temp- afc-oxygen sensor ect.There for, I would look
for something mechanical like ignition timing vaccum leaks,tune up parts
ect.When the van warms up, the temp 2 switch rehooks up the computer and
the commputer may compensate a little for some bad part.I bet yu are still
getting bad gas mileage.good luck,Roger