tmarat
Member
- Joined
- May 1, 2011
- Messages
- 48
- Reaction score
- 0
- City, State
- Atyrau
- Year, Model & Trim Level
- 2008 Ford Explorer 4.0
Happy new year everybody!
I have an issue with high fuel consumption. Currently it is winter time with temperatures about -10C to -16C/14F to 3F, and I am seeing about 28l/100km, 8 - 8.5mpg. I don't do a lot of idling for engine warming, but the trips are usually short, 7-8km, or about 5miles.
I see that bank two always has high ltft (long term fuel trims) 5-10, while bank one is usually 3-5. Ignition coil had a little crack just below where the ground connector (goes under the bolt), so I suspected maybe a spark issue, as insufficient fuel burn will also lead to positive ltft. Replaced ignition coil (motorcraft), spark plugs (denso iridium) and the spark wires (motorcraft). But this did not change anything, in fact right after replacement I had rough idle, which went away after some time (mostly, still some roughness from time to time, KAM reset through battery disconnect for about 15mins).
The O2 sensor for bank two seems to mostly show rich condition (0.7v), and does not fluctuate much. At idle it is pretty much at 0.7 and starts moving a bit only while driving, while the bank one sensors do move up and down. What I don't get is why then the ltft is still high? As the o2 is reading rich, shouldn't I be seeing negative fuel trim? At engine start I do hear pops from time to time suggesting some fuel is being burnt off in the exhaust. They are gone after warm up, but quick rev ups while stationary still lead to those pops again.
Tried testing the o2 sensor by disconnecting a vacum hose to see the reaction, below is a video. Is this o2 sensor functional or dead?
I have an issue with high fuel consumption. Currently it is winter time with temperatures about -10C to -16C/14F to 3F, and I am seeing about 28l/100km, 8 - 8.5mpg. I don't do a lot of idling for engine warming, but the trips are usually short, 7-8km, or about 5miles.
I see that bank two always has high ltft (long term fuel trims) 5-10, while bank one is usually 3-5. Ignition coil had a little crack just below where the ground connector (goes under the bolt), so I suspected maybe a spark issue, as insufficient fuel burn will also lead to positive ltft. Replaced ignition coil (motorcraft), spark plugs (denso iridium) and the spark wires (motorcraft). But this did not change anything, in fact right after replacement I had rough idle, which went away after some time (mostly, still some roughness from time to time, KAM reset through battery disconnect for about 15mins).
The O2 sensor for bank two seems to mostly show rich condition (0.7v), and does not fluctuate much. At idle it is pretty much at 0.7 and starts moving a bit only while driving, while the bank one sensors do move up and down. What I don't get is why then the ltft is still high? As the o2 is reading rich, shouldn't I be seeing negative fuel trim? At engine start I do hear pops from time to time suggesting some fuel is being burnt off in the exhaust. They are gone after warm up, but quick rev ups while stationary still lead to those pops again.
Tried testing the o2 sensor by disconnecting a vacum hose to see the reaction, below is a video. Is this o2 sensor functional or dead?