Understanding fuel trim! 

This a great explanation! You speak very clearly and it's nice to learn from a fellow female in this industry!!

Thanks for your visual aid presentation. it is always more helpful than just words.

Its called Open and Closed Loop, the condition you were explaining with regards to the cold start and the engine defaulting to a preprogrammed setting until it receives proper data from all the required sensors. Thoroughly enjoyed your presentation and the great illustrations. Very apparent that you have drawing skills too. Thank you for your time and effort.

Hi I am also a mechanic and absolutely love the easy to understand and basic way that you explain the way the E C U and its sensors work and the way the air and fuel mix works in relation to all of this you are clearly a very talented mechanic and if anytime my car goes wrong and im in your part of the world I will be sure to bring my car to you to fix keep up the good work !!!

Thanks so much!, I'd add when there is no a good fuel pressure the O2 will report lean condition.

We salute you!!! That was the best explanation of anything I seen this year!!One of the all time best!! Well done

Young lady, I like your presentation Style. Your voice is in the tembre that can appeal to both male and female. Your use of the board and the quality of your Blackboard is clear and to the point. You can build a niche for yourself. Don't be afraid to redo some other presentations in your own style. I look forward to more videos from you. Therefore I have subscribed.

Wau thank you so much for such professional explanation I have been studying mechanic for a couple years and I understand what you are talking about. You did great. I’m not a native English speaker sorry for any mistake. You got my like and subscription.

GREAT JOB!! thank You SOOooo Much!

Just subscribe ,just the facts I think I Love you 💖 you have made me proud when A woman explains men take hold and listen .WoW so good ! I just couldn't stop smiling ,God bless stay safe ,knowing that you are making a difference Thank you 💖

You are exactly amazing every body make it so damn difficult. This amazing hun gonna draw your diagram and use it

It's very rare to find a woman who understands mechanic.thanks

Thank You God Bless You for sharing l thought it was a mans world but where would we be without a woman at our side to all girls moms grandmas Richard thanks

Thanks 👍 very useful informative video . Salute to you sir 😘

I've been doing this for many years and suddenly this young lady made it all so clear Thank You.

Good Explanation thanks you very much

Wow thank you explaind very well !

Great job!

You certainly have perfected this subject with an awesome visual display with an inviting and warm personality.

Great video, beautifully explained. Subcribed!👏🏾👏🏾👌

Brilliant video, would love to see more on engine diagnostic basics along these lines. TC Annapolis, MD

Love the video thanks for share ur knowledge

Very Good, beginning to pick this up. CLosed Loop control system where the output control thee input. Much Love for your effort. X

clear and concise explanation thanks

Im going to follow you and learn from you 👍

Good explanation and nice draw ^^

Top style and information

Excellent video, simple clear instructions and great drawings really helps. Thank you

Even in what appears to be a sleep deprived state, very coherent and informative. It would be nice to see a brief follow up discussing a bit more about how individual components may fail and effects. (Yes this is some of that, but I'm sure there is more to be added and i think it would be better suited as a seperate video :) )

Thankx.. Great video.🐆🍁🍀🌹🌹

if vacuum leak, STFT will add more fuel right? thus highest fuel consumption? how about lean condition?

Thank you ms. Its well explained

Hi dear! 12:00 is this reflected in both banks? Or in one bank like in my case is in bank #1 I have a short term fuel trim -27.3% on bank#1 And it's on both sensors upstream and downstream That bank in my case is down by the pcm. Bank #2 is working. Then with my engine running I started desconecting Each cylinders on bank#2 and each cylinder miss fire But the engine won't shutt down! Guess what! Bank #1 started working... Then if I reconnect #2 bank #1 bank shutt down... I've been dealing with this for more than A year and i've learn about fuel trims and Everything related with and replacing parts And still!!!!! I just see your channel and I stop to see What you a women as a mechanic Can tell me!!!!! Thanks' in advance👣

Thanks, this video has given me a better understanding of fuel trims.

Hi didn't you forget that a lean condition can also be caused by too little fuel like weak pump clogged injectors or filter? Or viscera on a rich condition, like too little air??? And what about an exaust leak? That can cause confusion good job on some of the explanations tho

Thank you so much. I have a question what’s the definition of stokeyometric value? I don’t know how to spell it and I haven’t really found it. Thank you again, great tutorial. 👌😁

If a fuel filter clogged there would be a rich condition?

Good job. Thanks. Your drawing is awesome.

Intake leak should be after the sensors or they’ll read the xtra air

hey hi let talk about wide band o2 sensor,i like yr video

Enjoyed your visual and easy description of fuel trim. Hope to see more about auto sensors

Great video, I now understand fuel trim better.

thank you! excellent explanation!!! precise & to the point! great job!!

Very well done! You’re an excellent teacher!!!! More videos!!!

Great job looking forward to more of your videos.

so you're saying that - is rich and + is lean?

Meredith Good Evening and nice to meet you!

How to check diesel engine fuel trim

Not all vehicles utilize MAF sensors.

Good explanation

interesting but you forgot to mention the key element on a loop pcm/ ecu / ecm system which is the timer the computer uses to adjust, modify and compensate for the ideal fuel ratio (14:7:1). this is how it operates: once you start the engine your brain module wakes up and the timer starts. if after certain time your computer couldnt get certain values registered in parameters and according to sensor data written into the hardware being burned/ nonburned software then the module will go into a different parameter in order to compensate for the loss/ adding of, if theres any. (broken gasket, fuel leak, bad cat, vac leak, demaged sensor, etc) - if that doesnt work for it, then in certain more given time and the necessary space between data & parameters - the module again will go into another parameter and so on until it finally gets into limp mode (critical repair/service shop indicator mode) depending on what kind of situation is, the timer will reduce or enlarge these values and scales until it encounters its ideal values to work with priority parameters until the failure is fixed and new info is entered into it just by sensing data or updated/ flashed software into the brain module processor so the module restarts again with its new freshly updated data into its parameters. all its about time.

I thought the sin wave O2 graph was a result of the ECM adjusting fuel trims to alternate between rich/lean condition. I may be wrong, but I believe the O2 would show a steady line if it were not for the STFT being constantly adjusted up/down.

How can we not give thus a TU

You had me till the .50 mark. 14.7.1 fuels for some time have 10% ethanol so 14.1 AFR. I checked my gauage and tune and it is off when commanding 14.7.

You're a great artist.

Exelente video Gracias

Excellent explanation. Thanks.

With a well explained video like this witg good visual aids i dont know why you havent got more comments or subscribers...well done

Great video...but could you explain engine temp sensor and it's effect on fuel trim and would it create misfire under heavy load condition.

Can you e mail me a copy of this drawing.

Thank you Meredith's can a leaky or malfunction fuel injector cause the STFT to go up to 50% car feels like a misfire but no CEL, accelerates with small power or feels like getting stuck.

Hi. Can you send me a picture of the drawing?

14.7 is why the fuel economy is very aggressive for ford, isn’t it?

best overview on fuel trim I’ve seen.

GREAT VIDEO !!!!!!!!!!!!!!!!!!

Indepth

what does it mean when stft is less that 5% both neg and pos but ltft stays around -15% constant and lowers to -10% when accelerated?