High HC, negative long term fuel trim?
Discussion
Curiosity more than anything...
I've had my Twingo for over six years now, and its never been that great on fuel. Around 30 mpg most of the time, but I've chalked it down to being used in London most of it life, City driving isn't going to be great for mpg anyway.
It just had its MOT earlier in the week, straight through no problems (it always flies through its Mot).
But on its emissions it says....
Fast idle test.
CO max limit 0.200, actual limit 0.038
HC max limit 200, actual value 115
Lambda min 0.970, max 1.030, actual 0.994
Also this car has always had a negative long term fuel trim, six years ago it was -12%, its now sitting at -19%. Never any fault codes. It also has the weird trait where some days it flies along, loads of power. And other days it feels a bit lethargic. Its been to few different garages over the years, every one says its fine. Exhaust is always sooty.
Its a twingo 1.2 GT (1.2 TCE 100). Like I said, its just my curiosity more than anything.
I've had my Twingo for over six years now, and its never been that great on fuel. Around 30 mpg most of the time, but I've chalked it down to being used in London most of it life, City driving isn't going to be great for mpg anyway.
It just had its MOT earlier in the week, straight through no problems (it always flies through its Mot).
But on its emissions it says....
Fast idle test.
CO max limit 0.200, actual limit 0.038
HC max limit 200, actual value 115
Lambda min 0.970, max 1.030, actual 0.994
Also this car has always had a negative long term fuel trim, six years ago it was -12%, its now sitting at -19%. Never any fault codes. It also has the weird trait where some days it flies along, loads of power. And other days it feels a bit lethargic. Its been to few different garages over the years, every one says its fine. Exhaust is always sooty.
Its a twingo 1.2 GT (1.2 TCE 100). Like I said, its just my curiosity more than anything.
Those readings show everything is well within pass limits, so nothing to worry about there.
Your long term fuel trims basically mean the (IIRC) your putting in less fuel than you perhaps should be, but as long as your AFR/Lambda is right, which it is & your short term fuel trims are around zero the ECU is compensating correctly for everything that it needs to.
Your long term fuel trims basically mean the (IIRC) your putting in less fuel than you perhaps should be, but as long as your AFR/Lambda is right, which it is & your short term fuel trims are around zero the ECU is compensating correctly for everything that it needs to.
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