Quote:
Originally Posted by zmz0305
I mean, I don't quite understand the meaning of "rich" in here. Could you explain it a bit please? And how it could cause unburned fuel?
Sorry english is not my first language and I am kind of car noob here  . |
I'll butt in here .....
By "rich" they mean that the car is burning an AFR (air fuel ratio) that is heavy on the "fuel" part of the ratio.
In this case, a black, sooty deposit may show up on the tail pipe outlet.
Back-in-the-day, one could almost "measure" the AFR by looking at the inside of the tail pipe ....... if it was black, the engine was running rich, it was whitish, the engine was running "lean" ...... so, a light, smoke color deposit was "good".
The AFR could be changed by "adjusting" the carburetor(s) or the engine timing.
Today, I have no idea how the ECU (Engine Control Unit) alters the AFR.
However, someone in the know, will have to explain that to you ......
humfrz