| If the coolant thermostat and/or coolant temp sensor is faulty and keeps the engine below proper temp the ECU will keep the engine in warm up mode and not only consume more fuel but performance will suffer. Happened to my NA. Have you checked the mass airflow sensor? It could be faulty/dirty and not throw a code because it is not dead. Do you have any codes what are they? Did this performance deficiency happen gradually or all of a sudden? Have you checked the static timing with a strobe light? Should be 15 +/- degrees after warm up. Do a compression test if not resolved with the simplier items noted.
ZUL8TR in Orlando,FL |