Interior - Chrysler laser 1990 Technical Information Manual

Diaphragm
Fuel from delivery pipe
<Non-Turbo>
Fuel Supply and Fuel Pressure Control
A high-pressure type filter is installed at the delivery end of the
fuel pump.
The fuel pressure regulator maintains the pressure of fuel
delivered to the injectors at a constant level of 335 kPa (47.6
psi) (Non-Turbo models) or 255 kPa (36.3 psi) (Turbo models)
from intake
higher than the manifold internal pressure, thus keeping the
volume of fuel injected constant regardless of changes in the
manifold pressure.
The spring chamber is connected by a vacuum hose with the
intake air plenum thus its interior pressure is always controlled
by the manifold vacuum.
The manifold vacuum created in the chamber functions to
decrease the spring pressure which forces down the valve
actuated by a diaphragm.
If this pressure forcing down the valve becomes less than the
fuel pressure, the diaphragm is forced up, allowing excess fuel
to flow back through the return pipe to the fuel tank.
Level "A" in the diagram to the left denotes the pressure
gauge reading when the vacuum hose is disconnected, in other
words, when the manifold vacuum is not applied to the spring
chamber.
Level "B" denotes the pressure gauge reading when the
vacuum hose is connected:
l
-196 2
Positive