Jim Grant's Tech Tips
Impala, Plugged PCV System
have a '95 Chevy Impala and there is no vacuum from the vacuum port of
the throttle body to the PCV valve. Any suggestions on what the problem
is or repairs that are needed will be appreciated.......Frank
problem is likely due to a carbon build up, and this problem is not uncommon.
The build up is caused by moisture, gasoline vapors, exhaust gas and other
contaminates that normally form in the crankcase of an engine. The job
of the Positive Crankcase Ventilation (PCV) valve is to remove these gasses
and feed them back to the engine to be burned during combustion. As these
gasses travel through the PCV system they condense, collect and build-up
on the passage walls. Over time these deposits will become so great they
will restrict or even block the vacuum passage in a carburetor or fuel
injection throttle body. The fix requires removal of the throttle body,
cleaning the passages and a new gasket.