Pickup 2WD L4-155 2555cc 2.6L SOHC VIN E 2-bbl (1988)
seating the control valve.
Fig. 35 Bowl vent valve operation (vacuum > 2.0 in. Hg.)
3.
If intake manifold vacuum exceeds 2.0 in Hg (6.7 kPa, 1.0 psi), diaphragm A is pulled to the left and the inner float bowl passage is opened, Fig.
35. If intake manifold vacuum decreases temporarilly while the engine is operating the check valve will maintain 2.0 in Hg (6.7 kPa, 1.0 psi) of
vacuum to hold the inner float bowl passage open.
Fig. 36 Bowl vent valve operation (vacuum < 0.4 in. Hg.)
4.
When the engine is turned off intake manifold vacuum falls below 0.4 in. Hg (1.3 kPa, 0.2 psi). Diaphragm B, Fig. 36 moves to the left opening
the control valve venting the vacuum on diaphragm A. The BVV then moves to the right isolating the carburetor inner vent passage from the
atmosphere.
