Installation manual

90-898305

4-28

Fuel Pressure Regulator

• Calibrated to raise fuel pressure 10 psi above air pressure

• Uses both air & internal spring pressure to control fuel pressure

♦ Internal spring calibrated at 10 pounds resistance

♦ Spring holds the diaphragm against seat

♦ Contact between diaphragm and seat closes the passage between

incoming fuel (from the electric fuel pump) and the fuel return passage

• When the engine isn’t running (no air pressure on spring side of

diaphragm) the fuel pressure required to move the diaphragm is 10 psi

• When the engine is running, air pressure from the air compressor (80 psi)

is routed to the spring side of the diaphragm

• The air pressure (80 psi) and the spring pressure (10 psi) combine to

regulate the fuel system pressure to 90 psi…or 10 psi than the air

pressure in the DFI system/fuel rails

Sectional View

a – 10 lb. spring (15 lb. spring on 1.5L models)

b - Diaphragm

c - Fuel return line to VST

d - Air passage

e - Fuel passage

f - Excess fuel return opening

Notes

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