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Home >> Porsche >> 2017 >> Macan GTS >> Repair and Diagnosis >> External Pages >> Different car >> Section 686 (Fuel Tank & Lines - V6 S/C 3.0L Petrol -- Discovery/L462) >> Fuel Tank And Lines - V6 S/C 3.0L Petrol >> Diagnosis And Testing >> Symptom Chart

Symptom Chart

WARNING: This page is about a different car, the 2018 Land Rover Discovery and 2017 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.
SYMPTOM POSSIBLE CAUSES ACTION
Engine cranks, but does not fire
  • Engine breather system disconnected/restricted
  • Ignition system
  • Fuel system
  • Electronic engine control
Ensure the engine breather system is free from restriction and is correctly installed. Check for ignition system, fuel system and electronic engine control DTCs and refer to the relevant DTC index
Engine cranks and fires, but will not start
  • Evaporative emissions purge valve
  • Fuel pump
  • Spark plugs
  • HT short to ground (tracking) check rubber boots for cracks/damage
  • Ignition system
Check for evaporative emissions, fuel system and ignition system related DTCs and refer to the relevant DTC index
Difficult cold start
  • Engine coolant level/antifreeze content
  • Battery
  • Electronic engine controls
  • Fuel pump
  • Purge valve
Check the engine coolant level and condition. Ensure the battery is in a fully charged and serviceable condition. Check for electronic engine controls, engine emissions, fuel system and evaporative emissions system related DTCs and refer to the relevant DTC index
Difficult hot start
  • Injector leak
  • Electronic engine control
  • Purge valve
  • Fuel pump
  • Ignition system
Check for injector leak, install new injector as required. Check for electronic engine controls, evaporative emissions, fuel system, ignition system and engine emission system related DTCs and refer to the relevant DTC index
Difficult to start after hot soak (vehicle standing, engine off, after engine has reached operating temperature)
  • Injector leak
  • Electronic engine control
  • Purge valve
  • Fuel pump
  • Ignition system
Check for injector leak, install new injector as required. Check for electronic engine controls, evaporative emissions, fuel system, ignition system and engine emission system related DTCs and refer to the relevant DTC index
Engine stalls soon after start
  • Breather system disconnected/restricted
  • Engine control module relay
  • Electronic engine control
  • Ignition system
  • Air intake system restricted
  • Air leakage
  • Fuel lines
Ensure the engine breather system is free from restriction and is correctly installed. Check for electronic engine control, ignition system and fuel system related DTCs and refer to the relevant DTC index. Check for blockage in air filter element and air intake system. Check for air leakage in air intake system
Engine hesitates/poor acceleration
  • Fuel pressure, fuel pump, fuel lines
  • Injector leak
  • Air leakage
  • Electronic engine control
  • Throttle motor
  • Restricted accelerator pedal travel (carpet, etc)
  • Ignition system
  • Transmission malfunction
Check for fuel system related DTCs and refer to the relevant DTC index. Check for injector leak, install new injector as required. Check for air leakage in air intake system. Ensure accelerator pedal is free from restriction. Check for electronic engine controls, ignition, engine emission system and transmission related DTCs and refer to the relevant DTC index
Engine backfires
  • Fuel pump/lines
  • Air leakage
  • Electronic engine controls
  • Ignition system
  • Sticking variable camshaft timing hub
Check for fuel system failures. Check for air leakage in intake air system. Check for electronic engine controls, ignition system and variable camshaft timing system related DTCs and refer to the relevant DTC index
Engine surges
  • Fuel pump/lines
  • Electronic engine controls
  • Throttle motor
  • Ignition system
Check for fuel system failures. Check for electronic engine controls, throttle system and ignition system related DTCs and refer to the relevant DTC index
Engine detonates/knocks
  • Fuel pump/lines
  • Air leakage
  • Electronic engine controls
  • Sticking variable camshaft timing hub
Check for fuel system failures. Check for air leakage in intake air system. Check for electronic engine controls and variable camshaft timing system related DTCs and refer to the relevant DTC index
No throttle response
  • Electronic engine controls
  • Throttle motor
Check for electronic engine controls and throttle system related DTCs and refer to the relevant DTC index
Poor throttle response
  • Breather system disconnected/restricted
  • Electronic engine controls
  • Transmission malfunction
  • Traction control event
  • Air leakage
Ensure the engine breather system is free from restriction and is correctly installed. Check for electronic engine controls, transmission and traction control related DTCs and refer to the related DTC index. Check for air leakage in intake air system