Prozento
Senior Member
- First Name
- Alex
- Joined
- May 7, 2018
- Threads
- 32
- Messages
- 132
- Reaction score
- 37
- Location
- Israel
- Vehicle(s)
- Civic FD
- Thread starter
- #1
Hello CivicX community
I decided to make a thread about an official normal values for K.count/misfire and fuel trims that I found in Honda service books for our model. Take this info as an answer for when you really need to worry and when its just something you need to keep your eye on. Hope it will help for someone here.
__________________________________________________________________________________________
Fuel trim - too high:
Malfunction Threshold: Long term fuel trim is higher than 1.32 (+32 %) / 1.33 (+33 %) - 1.5 / 2.0 Engines
Fuel trim - too low:
Malfunction Threshold: Long term fuel trim is 0.79 (-21 %) or less.
Possible Cause:
Fuel pump failure
Injector failure
Fuel pressure regulator failure
Fuel line failure
Fuel supply system failure
Mass airflow (MAF) sensor range/performance problem
Manifold absolute pressure (MAP) sensor range/performance problem
A/F sensor (sensor 1) failure
Secondary HO2S (sensor 2) failure
Vacuum hose misinstalled
Throttle body air leak
Intake manifold air leak
EVAP canister purge valve failure
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
____________________________________________________________________________________________
Random Misfire; No. 1/2/3/4 Cylinder Misfire:
Malfunction Threshold: The number of misfires versus engine revolutions is equal to or greater than these values
1. Misfire Type 1 (Severe) - Per 200 revolutions 17 - 89 times (Depending on engine speed and load).
2. Misfire Type 2 (Light) Per 1,000 revolutions 77 times
Possible Cause:
Ignition system failure
Fuel supply system failure
Intake air system failure
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
____________________________________________________________________________________________
So these are the official values. Hope now we will be more relaxed when our fuel trims inside the city jump to -10% or when 5 misfires happen after 2 hours of driving.
P.S.
Another good threads:
Fuel trims
https://www.27won.com/blog/yeah-but-what-are-your-fuel-trims
Misfire
https://www.civicx.com/threads/what-is-knock-count-and-knock-control-defined.38412/
Knock control Ktuner files
http://www.ktuner.com/KTunerHelp/ignition_timing_and_knock_control.htm
I decided to make a thread about an official normal values for K.count/misfire and fuel trims that I found in Honda service books for our model. Take this info as an answer for when you really need to worry and when its just something you need to keep your eye on. Hope it will help for someone here.
__________________________________________________________________________________________
Fuel trim - too high:
Malfunction Threshold: Long term fuel trim is higher than 1.32 (+32 %) / 1.33 (+33 %) - 1.5 / 2.0 Engines
Fuel trim - too low:
Malfunction Threshold: Long term fuel trim is 0.79 (-21 %) or less.
Possible Cause:
Fuel pump failure
Injector failure
Fuel pressure regulator failure
Fuel line failure
Fuel supply system failure
Mass airflow (MAF) sensor range/performance problem
Manifold absolute pressure (MAP) sensor range/performance problem
A/F sensor (sensor 1) failure
Secondary HO2S (sensor 2) failure
Vacuum hose misinstalled
Throttle body air leak
Intake manifold air leak
EVAP canister purge valve failure
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
____________________________________________________________________________________________
Random Misfire; No. 1/2/3/4 Cylinder Misfire:
Malfunction Threshold: The number of misfires versus engine revolutions is equal to or greater than these values
1. Misfire Type 1 (Severe) - Per 200 revolutions 17 - 89 times (Depending on engine speed and load).
2. Misfire Type 2 (Light) Per 1,000 revolutions 77 times
Possible Cause:
Ignition system failure
Fuel supply system failure
Intake air system failure
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
____________________________________________________________________________________________
So these are the official values. Hope now we will be more relaxed when our fuel trims inside the city jump to -10% or when 5 misfires happen after 2 hours of driving.
P.S.
Another good threads:
Fuel trims
https://www.27won.com/blog/yeah-but-what-are-your-fuel-trims
Misfire
https://www.civicx.com/threads/what-is-knock-count-and-knock-control-defined.38412/
Knock control Ktuner files
http://www.ktuner.com/KTunerHelp/ignition_timing_and_knock_control.htm
Sponsored
Last edited: