Henrique - RS
NAXJA Forum User
- Location
- Brazil
1998 XJ 4.0 Stock Engine
5 Speed
Hollowed Cat
Hello everyone,
My 98' has been struggling while taking off after a red light for instance. Sometimes my engine would even stall. Sometimes it runs perfectly fine like today all day.... Never had an issue while on high RPMs and load so I guess that may rule out fuel pump issues, right?
Cleaned my IAC, changed TPS, didnt find any vacuum leaks by spraying carb cleaner around vac lines, injectors, brake booster, CCV, etc...
My long term fuel trim is up to 20%, while the STFT oscillates around -1+3%. My upstream o2 readings seem to be a little bit lazy, even though they are in the expected voltage range. Since downstream o2 does not control fuel AND I have no cat, I can assume we are not worried about downstream (B1S2) o2 readings.
Readings at idle:
Does anything seem out of usual? I guess I should replace my upstream O2 sensor because of it's "lazyness" in oscilating. What you guys think?
TIA
5 Speed
Hollowed Cat
Hello everyone,
My 98' has been struggling while taking off after a red light for instance. Sometimes my engine would even stall. Sometimes it runs perfectly fine like today all day.... Never had an issue while on high RPMs and load so I guess that may rule out fuel pump issues, right?
Cleaned my IAC, changed TPS, didnt find any vacuum leaks by spraying carb cleaner around vac lines, injectors, brake booster, CCV, etc...
My long term fuel trim is up to 20%, while the STFT oscillates around -1+3%. My upstream o2 readings seem to be a little bit lazy, even though they are in the expected voltage range. Since downstream o2 does not control fuel AND I have no cat, I can assume we are not worried about downstream (B1S2) o2 readings.
Readings at idle:


Does anything seem out of usual? I guess I should replace my upstream O2 sensor because of it's "lazyness" in oscilating. What you guys think?
TIA