System Inspection

■ Fuel Filter Restriction Inspection 

Remove the fuel pump and check fuel filter for debris and clogging of the fuel supply line.

■ Fuel Level Inspection 

If there is a significant drop in fuel pressure during heavy acceleration (ramp, steep hill, etc.), could be due to fuel pump degradation.

■ Low Fuel Pressure Supply Line Leak or Restriction 

Low-pressure fuel supply line damage and or restriction can result in low fuel pressure drop.

■ Fuel Pressure Regulator Inspection 

• Check Fuel Pressure Regulator performance by measuring voltage and current.
  1. Back probe and measure voltage by using VMI and connecting channel A (+) voltage probe to High side and channel A (-) voltage prove to Low side of fuel pressure regulator.
  2. Measure operation current by using Low Current Sensor Module.
     Fig 1: Scantool Display - Signal Waveform & Data (Engine Idle After Warm Up)

     Courtesy of KIA MOTORS AMERICA, INC.
     Fig 2: Scantool Display - Signal Waveform & Data (Approx 2000 RPM)

     Courtesy of KIA MOTORS AMERICA, INC.
  3. Are all listed items normal?

     YES 

     • Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

     NO 

     • Recheck the listed items from this troubleshooting guide steps, and replace or repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.