Chevrolet IMPALA 3.9L 2009, Руководство по установке системы CNG, Страница: 13 / 32

© 2009 IMPCO Technologies, Inc. -11- 2009 3.5/3.9L Impala CNG
B. Intake Manifold, Ignition Coil Pack and Air Filter Housing Removal:
Prior to any disassembly, clean the engine and engine compartment (with engine degreaser where
necessary). Disconnect the negative battery cable followed by the positive battery cable and remove
the battery from the vehicle. Following the manufacturer’s service manual instructions, remove the
upper intake manifold, then the ignition coil pack. Remove the air filter housing to expose the ECM.
C. Intake Manifold Modifications:
1) Using a straight edge, draw two lines along
the intake manifold keeping the straight
edge just inboard of the runner numbers.
Using a center punch, make a small dimple
where the lines intersect in the photo
(arrows).
NOTE: Lower intake manifold has been
removed from the engine for clarification. DO
NOT remove the lower intake manifold from the
engine.
2) Before drilling & tapping the runners, cover
all of the intake ports and OEM injector
holes except for those on the runner you
will be drilling & tapping. Using a rubber
tipped blow gun, blow air into the runner
being drilled and tapped so all metal chips
will be carried out of the runner through the
intake runner opening. Also, incorporating
a wet/dry vacuum on the intake runner
opening will help evacuate metal chips from
the runner.
IMPORTANT: Make sure the intake valve
for the cylinder you are working on is
completely closed. If not, rotate the engine by
hand until it is.
BE SURE to wear goggles and a face mask
to protect your eyes from flying particles.
3) While blowing air through one of the
runners, and using one of the 5mm drills in
the Sequent Installer’s Tool Kit, drill through
the top intake manifold runner wall keeping
the drill perpendicular to the runner face.
DO NOT drill into the bottom wall of the
runner.