Check Fuel Pressure

IG KEY "OFF".
Disconnect fuel pump relay from junction box in passenger compartment.
Start engine and await until engine is off and then, IG "OFF"
Connect fuel pump relay again.
Connect fuel pressure gauge on the fuel filter with fuel pressure gauge adaptor.
Start engine again and measure fuel pressure.
Specification: Approx. 3.5kg/cm²

Fig 1: Checking Fuel Pressure Using Fuel Pressure Gauge
Courtesy of KIA MOTORS AMERICA, INC.
Is the fuel pressure normal?
YES

Go to "COMPONENT INSPECTION " procedure.

NO

Check any damage of fuel return hose or pipe.

Check any sticking of the valve in the fuel pressure regulator.

Repair or replace as necessary, and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.