air/fuel change slighty with colder weather

[mikey4410]

Anybody elses changed much with the cold weather ??

I know its to be expected and what not.

Mine about 3 weeks ago was 11.00 @ wot

Now its 11.3 wof.

[maddox710]

Much colder dense air

[mikey4410]

yeap indeed,makes it slightly leaner mixture.

Guess i am the only one,lol

[JayJ]

Noticed a leaner mixture also with mine. Temp has been dropped about 5 degrees from Tuesday when I was last driving.

[GP82]

Is this from a stock ecu?

[JayJ]

I have JAM. Still runs quite rich, but leaner than it used to.

[GP82]

Okay thanks, would have thought the stock or Plug and play ecu will compensate for the extra oxygen and keep the A/F consistant so as not to go leaner.

[AdamB]

It's hard to say exactly what the ecu will do in closed loop unless you were the code programmer

[GP82]

For sure, no doubt about that, but i was just questioning why the ecu would let the cylinder mixture run leaner when there is more oxygen being introduced. I guess it's not much to worry about and the A/F could be affected by 101 number of factors.

[AdamB]

It will let it run as lean as the engine will allow until knock is detected, only then will the ecu pull timing to save the engine, although this very rarely happens because the engines are such low compression anyway.

The leaner the mixture the more torque you make (up to a point), so there's no need for the ecu to compensate for anything.

That's my take on things anyway