Engine Hesitates/Poor Acceleration

Check for clutch slipping or brakes dragging.
Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
Check air filter.
Check for leakage or clogging between air filter and turbocharger inlet and between turbocharger outlet and cylinder head (if equipped).
Verify secondary ignition system performance and timing.
Verify proper compression and valve clearance.
Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
Check for clogged fuel injectors.
Check variable induction system (if equipped).
Check power to ECU via fusible links, fuses and EFI main relay.
Check airflow meter, coolant temperature sensor, air temperature sensor and throttle position sensor.
Check injection signal circuit.