What to Do When the Engine Idles Roughly When Cold but Smoothly When Warm?
1 Answers
Specific steps for addressing rough idle when cold but smooth idle when warm are as follows: 1. First, use an automotive diagnostic tool to check for any engine fault codes. If present, identify which sensor is faulty and proceed with the corresponding repairs. 2. If there are no engine fault codes, then check for any engine misfires. If misfires are detected, inspect the spark plugs, ignition wires, ignition coils, crankshaft position sensor, and ignition coil circuits. Perform the necessary repairs or replacements. 3. If no misfires are detected, proceed to inspect the fuel delivery system. Remove the fuel line and connect a fuel pressure gauge to conduct a pressure test. A normal reading should be between 270Kpa and 350Kpa. If the fuel pressure is low, inspect the fuel pump and carry out the necessary repairs. 4. If the fuel delivery system is functioning properly, check whether the throttle body is clean. If it is dirty or damaged, clean it thoroughly using carburetor cleaner. Then, verify if the idle air control valve is operational. If it is not working, replace it. 5. If the throttle body and idle air control valve are functioning correctly, inspect the fuel injectors for proper operation or blockages. If the injectors are not working or leaking abnormally, check the injector wiring and perform the necessary repairs. 6. If the fuel injectors are functioning properly, check the compression of each cylinder. A compression reading of 8 or higher is considered normal. If the compression is insufficient, take the vehicle to a repair shop for the necessary repairs.
