arizonanissan wrote: ↑
Thu Apr 29, 2021 9:07 pm
Just started my car in the garage and what i find is when the AC is off the engine is quiet however when i turn the AC on the injectors get louder!! The noise goes away afet say 5 mins!
If it's on cold start then the engine is running "open loop" (all 4 injectors firing together) and the ECM will bump up the engine speed when the compressor runs. That will make the already-loud injectors a bit louder. Once the car warms up and the loop closes, the injectors fire individually and quiet down. Perfectly normal.