Joined
·
10,939 Posts
The engine will maintain the same speed where it idles smoothly during the first minute of warm-up. This gets stored in the ECU as the cold start trim. When the air is warmer, the amount of fuel results in a higher idle speed. There is nothing wrong with the system, it is just using the cold start idle fuel trim setting stored in the ecu.
If you were to reset the ecu correctly, it will behave differently but when winter comes you might end up with an engine running too lean and not pulling smoothly when cold. My car is doing this now, since my turbo replacement in january *(which is when us below the equator have summer) and ecu reset which followed. My car now during winter starts up quite easily, idles at 750rpm but for the first minute it will not easily pull from below 1500rpm.
If you were to reset the ecu correctly, it will behave differently but when winter comes you might end up with an engine running too lean and not pulling smoothly when cold. My car is doing this now, since my turbo replacement in january *(which is when us below the equator have summer) and ecu reset which followed. My car now during winter starts up quite easily, idles at 750rpm but for the first minute it will not easily pull from below 1500rpm.
