- Joined
- Oct 17, 2011
- Messages
- 755
- Reaction score
- 12
- Points
- 18
- Location
- New Joisey
- Vehicle Year
- 1987
- Make / Model
- Ford
- Engine Size
- 2.9L
- Transmission
- Manual
2002 Explorer 4.6L V8
Chasing a problem where vehicle seems to run fine but when keying off then trying to restart after a 10 minute drive it dies. I am trying to understand the fuel trim values as relates to being lean or rich. I did get a P0171 code at one point suggesting lean, likely a vacuum leak.
In the process I got another MAF sensor. Original sensor typically shows some positive long term trim values. 5% to 10%. Short term trim values are about eh same but sometimes go negative.
If I swap for a new sensor, the short term trim values go up to 30% even as high as 40% and the long term values typically drop to 0% and hold so steady that it seems it isn't trusting the readings it is getting.
Vehicle seems to run fine with either sensor once RPMs are up over 1200. At idle vehicle doesn't want to run with either sensor.
trying to get some insight to understand the values.
Thanks,
Andrea
Chasing a problem where vehicle seems to run fine but when keying off then trying to restart after a 10 minute drive it dies. I am trying to understand the fuel trim values as relates to being lean or rich. I did get a P0171 code at one point suggesting lean, likely a vacuum leak.
In the process I got another MAF sensor. Original sensor typically shows some positive long term trim values. 5% to 10%. Short term trim values are about eh same but sometimes go negative.
If I swap for a new sensor, the short term trim values go up to 30% even as high as 40% and the long term values typically drop to 0% and hold so steady that it seems it isn't trusting the readings it is getting.
Vehicle seems to run fine with either sensor once RPMs are up over 1200. At idle vehicle doesn't want to run with either sensor.
trying to get some insight to understand the values.
Thanks,
Andrea