How Rich Is Too Rich?

[Danger_GT4]

evenin troops

just thought i would get this one on here, after speaking with GTForbes whos helped alot, we did a bit of testing on my four and after hooking up a lambda sensor we found that im runnin quite rich at high revs. idling and normal driving was ok (around the 14-15 mark - what ever the units are) but high revs i was getting higher results resulting in overfuelling, i cant remember the exact number as i was driving and gtforbes had the guage (mate if you can reply to this post with the numbers that would be great)

so ultimately how rich is too rich where fuellig is concerned? and how is this tweaked?

Cheers

[GTForbes]

the numbers are a ratio 14:1 oxygen:fuel and the numbers were going down as in less oxygen and loads of fuel, i think my gauge goes down to 10.5 and you were beyond that

[dawesy]

if its contant <10.5 then yes its a bit too rich. mine does drop to 9.0 when you hit the gas but its more of a blip and soon settles at around 11.5-12.2 on full boost

[Danger_GT4]

if its contant <10.5 then yes its a bit too rich. mine does drop to 9.0 when you hit the gas but its more of a blip and soon settles at around 11.5-12.2 on full boost

cheers guys, is it easy enough to tweak this problem if so how do you?

thanks

[Parts-King]

Did anyone else think this thread was about being too money rich? If only I had bought a lottery ticket................

Kingo

[Danger_GT4]

Did anyone else think this thread was about being too money rich? If only I had bought a lottery ticket................

Kingo

:P oops ma bad!

[dawesy]

if its a stock ecu then there is no way to tweak it. it is possible that the airflow meter is out or even the wideband you used requires calibration. it is possible apparently to alter the AFM but unsure of what's needed to do it. might be worth giving it a service first.

[Danger_GT4]

if its a stock ecu then there is no way to tweak it. it is possible that the airflow meter is out or even the wideband you used requires calibration. it is possible apparently to alter the AFM but unsure of what's needed to do it. might be worth giving it a service first.

yeah its stock ecu i have (well i assume) i wonder would it have anything to do with the fact that i have a piper X air filter on but its not boxed off or anything so it will just be suckin in all that hot air, would that have anything to do with the mixture ratio? or would the mixture only be effected if it was really cold air that was gettin sucked in? also another point to add not sure if i mentioned it before, when we did our testing with the lambda sensor, i had just reset the ecu so could it have anything to do with the ecu learning? or am i talkin out my hole now?

any one know what the price of a service would be? roughly?

Cheers

[Sketchy]

The ecu will put extra fuel in for higher intake temps in order to help cooling in the cylinder and prevent det.

Having said that every Stock ECU four i've seen on the rolling road goes well into the 10:1's. The stock ecu is really bad for over fueling I guess toyota decided it would be better to be safer than have a little extra power.

This is further enforced by the amount of extra power you can pick up simply by fitting and correctly mapping an aftermarket ECU normally you'll see at least around a 30BHP increase on this alone.

As for weather the stock ecu is too rich personally I'd say yes. for best power on a turbo engine you should be looking to have around 12.6:1 on boost although most mappers will drop to the high 11:1's to keep things a little on the safe side.