That is a cool toy. I'll help where I can.
Long term fuel trim is what the computer has learned over time (based on O2 readings). Your base fuel maps are programed into the ecu. Say you have a long term fuel trim of +5%. Your MAF is reading 2.0 volts and the base program says to open the injectors for 20 milliseconds (completly making up numbers). The long term correction says you should open the injectors for 21 milliseconds instead of 20 ms. Then the O2 sensor gives feedback on the result for short term corrections.
The FSM talks about the correction factors. I'll look these up later and tell you whats in there. I've gotta go now.
Probably not. 15 degrees is just your base timing (idle, no load). At higher rpm you are running more advance. I dont remember how load changes the advance. SCC discussed this somewhere. I'll see if I can find it later.
Short term fuel trim is the change in fuel required (from the expected value based on MAF voltage) to make the O2 sensor happy. Short term fuel trim will be reset next trip.
Long term fuel trim is what the computer has learned over time (based on O2 readings). Your base fuel maps are programed into the ecu. Say you have a long term fuel trim of +5%. Your MAF is reading 2.0 volts and the base program says to open the injectors for 20 milliseconds (completly making up numbers). The long term correction says you should open the injectors for 21 milliseconds instead of 20 ms. Then the O2 sensor gives feedback on the result for short term corrections.
The FSM talks about the correction factors. I'll look these up later and tell you whats in there. I've gotta go now.
