All of this because of a converter install??
Originally Posted by MNR-0
Did you raise your low RPM misfire limits to 32767 on the cylinder misfire detection table?
James
TECH Enthusiast
Joined: Mar 2004
Posts: 647
Likes: 0
From: Australia
I think you misunderstand the concept behind misfires. All cars misfre - no exception. It's normal - you won't get rid of all of it. Just because it does or deosnt register on a scan tool is no indication it is not happening.
What is different from one car to the next is the level/intensity of the misfire. Raising the limits will do no harm to your car, engine, tune etc.. and quite possibly stop this frustration for you once and for all.
Its a quick win if it works. If it doesn't, move on...
So why wait?
What is different from one car to the next is the level/intensity of the misfire. Raising the limits will do no harm to your car, engine, tune etc.. and quite possibly stop this frustration for you once and for all.
Its a quick win if it works. If it doesn't, move on...
So why wait?
Originally Posted by MNR-0
I think you misunderstand the concept behind misfires. All cars misfre - no exception. It's normal - you won't get rid of all of it. Just because it does or deosnt register on a scan tool is no indication it is not happening.
What is different from one car to the next is the level/intensity of the misfire. Raising the limits will do no harm to your car, engine, tune etc.. and quite possibly stop this frustration for you once and for all.
Its a quick win if it works. If it doesn't, move on...
So why wait?
What is different from one car to the next is the level/intensity of the misfire. Raising the limits will do no harm to your car, engine, tune etc.. and quite possibly stop this frustration for you once and for all.
Its a quick win if it works. If it doesn't, move on...
So why wait?
Thank for your insite.
James
I don't understand the STFT/LTFT 1, 2, 3, 4 bit.
1, 2, OK if these are the banks. 3, 4???
Idle hunting -is- going to be made worse with the
lightweight converter. Mine did it with the TCI and
I had to bump up RPM and base airflow targets.
Cold is worse because the engine needs more air,
acts "soggier" and you have less flywheel mass to
ride out the yo-yo action if any.
Explain better the STFT/LTFT stuff. Relate the trims
to operating MAP/RPM, see whether there is a low
end specific airflow error. Look at real time O2 volts
for sanity, make sure you don't have one bank open
loop from some installation "oops" or something.
Look at the misfire current cylinder mode values,
all 8 cylinders, about idle and especially when you
are stumbling. The key is any stark difference from
cylinder to cylinder, which might point to a weak
sister.
1, 2, OK if these are the banks. 3, 4???
Idle hunting -is- going to be made worse with the
lightweight converter. Mine did it with the TCI and
I had to bump up RPM and base airflow targets.
Cold is worse because the engine needs more air,
acts "soggier" and you have less flywheel mass to
ride out the yo-yo action if any.
Explain better the STFT/LTFT stuff. Relate the trims
to operating MAP/RPM, see whether there is a low
end specific airflow error. Look at real time O2 volts
for sanity, make sure you don't have one bank open
loop from some installation "oops" or something.
Look at the misfire current cylinder mode values,
all 8 cylinders, about idle and especially when you
are stumbling. The key is any stark difference from
cylinder to cylinder, which might point to a weak
sister.
Originally Posted by jimmyblue
I don't understand the STFT/LTFT 1, 2, 3, 4 bit.
1, 2, OK if these are the banks. 3, 4???
Idle hunting -is- going to be made worse with the
lightweight converter. Mine did it with the TCI and
I had to bump up RPM and base airflow targets.
Cold is worse because the engine needs more air,
acts "soggier" and you have less flywheel mass to
ride out the yo-yo action if any.
Explain better the STFT/LTFT stuff. Relate the trims
to operating MAP/RPM, see whether there is a low
end specific airflow error. Look at real time O2 volts
for sanity, make sure you don't have one bank open
loop from some installation "oops" or something.
Look at the misfire current cylinder mode values,
all 8 cylinders, about idle and especially when you
are stumbling. The key is any stark difference from
cylinder to cylinder, which might point to a weak
sister.
1, 2, OK if these are the banks. 3, 4???
Idle hunting -is- going to be made worse with the
lightweight converter. Mine did it with the TCI and
I had to bump up RPM and base airflow targets.
Cold is worse because the engine needs more air,
acts "soggier" and you have less flywheel mass to
ride out the yo-yo action if any.
Explain better the STFT/LTFT stuff. Relate the trims
to operating MAP/RPM, see whether there is a low
end specific airflow error. Look at real time O2 volts
for sanity, make sure you don't have one bank open
loop from some installation "oops" or something.
Look at the misfire current cylinder mode values,
all 8 cylinders, about idle and especially when you
are stumbling. The key is any stark difference from
cylinder to cylinder, which might point to a weak
sister.
James
Here it is:
DTC that caused the freeze frame data:
PO300
TP:0.0%
Engine RPM:744
Load value:3.9%
Air flow rate:10.40 GR/SEC
Map sensor:42 KPA
Coolant temp:78º
STFT #1: 0.8%
LTFT #1: 8.5%
STFT #2: 0.8%
LTFT #2: 7.8%
STFT #3: -96.7%
LTFT #3: 0.0%
STFT #4: -89.7%
LTFT #4: 15.6%
Vehicle speed: 1mph
Fuel system: #1 & #2 open
This is the latest datd from the other night.
James
DTC that caused the freeze frame data:
PO300
TP:0.0%
Engine RPM:744
Load value:3.9%
Air flow rate:10.40 GR/SEC
Map sensor:42 KPA
Coolant temp:78º
STFT #1: 0.8%
LTFT #1: 8.5%
STFT #2: 0.8%
LTFT #2: 7.8%
STFT #3: -96.7%
LTFT #3: 0.0%
STFT #4: -89.7%
LTFT #4: 15.6%
Vehicle speed: 1mph
Fuel system: #1 & #2 open
This is the latest datd from the other night.
James
