changing tetex render engine

It seems that in the last update to tetex(3) pdfetex was set 
as the default render engine for tex.  I am having problems 
with it in that it doesn't interpret environment variables 
in the tex files.  The old engine(etex) interpreted them 
properly.  Is there a way to switch back to etex or get 
pdfetex to interpret the environment variables?  Thank you.
-- 
Scott Henson
LCSEE Systems Staff
WVU MAE Undergraduate
Ubuntu User