Fuel System Inspection

Refer to "Release Residual Pressure In Fuel Line " and release the residual pressure in fuel line.
CAUTION: When removing the fuel pump relay, a DTC may set. Delete the code with the KDS after completing fuel system inspection.
Install the Special Service Tool (SST).
1. Disconnect the fuel feed tube from the high pressure fuel pump.
  CAUTION: There may be some residual pressure even after releasing residual fuel pressure in fuel system. Therefore, cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.
2. Install low side fuel gauge to measure the fuel pressure in between the fuel feed tube and the high pressure fuel pump (refer to figure below).
Courtesy of KIA MOTORS AMERICA, INC.
Inspect for fuel leakage on connections among the fuel feed tube, the high pressure fuel pump, and the SST components with Ignition "ON".

Measure fuel pressure.

Start the engine and measure the fuel pressure at idle.

Specification : Fuel Pressure - 338 ~ 348 kPa (3.45 ~ 3.55kg/cm² )

NOTE: If the fuel pressure differs from the standard value, repair or replace the related parts (refer to the table below).

Fuel Pressure	Cause	Related Parts
Too Low	Fuel Filter Clogged	Fuel Filter
Too Low	Fuel Leakage	Fuel Pressure Regulator
Too High	Fuel Pressure Regulator Stuck	Fuel Pressure Regulator

Stop the engine, and then check for the change in the fuel pressure gauge reading.

Standard Value: The gauge reading should hold for about 5 minutes after the engine stops

NOTE: If the gauge reading is not held, repair or replace the related parts (refer to table below).

Fuel Pressure (After Engine Stops)	Cause	Related Parts
Fuel Pressure Drops Slowly	Leakage on injectors	Injectors
Fuel Pressure Drops Immediate	Check valve of fuel pump stuck open	Fuel Pump

Is the fuel pressure value within specification?
Good
- Go to "WIRING INSPECTION " procedure.
No Good
- Repair as necessary and go to "VERIFICATION OF REPAIR " procedure.