1. GENERAL INFORMATION Downtown 300i ABS POOR PERFORMANCE AT LOW AND IDLE SPEED Possible cause 1. Check ignition timing Incorrect Improper ignition timing Correct 2. Inspect the fuel flow Abnormal Faulty pressure regulator Normal 3. Inspect the fuel injector Abnormal Faulty injector Normal 4. Check for leaks in the intake pipe Leaking Loose insulator clamp Damage insulator No leak 5. Perform spark test Weak or intermittent spark Faulty the spark plug Faulty carbon or wet fouled spark plug Faulty ECU Faulty ignition coil Faulty ignition pulse generator Faulty ignition switch Loose or disconnected spark plug wires Good spark 1-19