A/F ratio

Jordo! · 10-03-2014, 01:37 PM

At idle and low load, it's going to hover around 14.7:1.

On tip in, AFR might enrichen (or briefly skew lean, then enrichen, which I believe is what you found in 20% TPS to WOT), then move towards target (depends on load -- richer at moderate to high load).

On throttle lift, fuel will cut, so it will read lean on coast down, returning to stoich as you approach idle.

Anyway, unless you have changed the diameter of the MAF tubes from OEM, or have a sensor issue or vacuum leak, it should trim (without issue) to various targets in ECU fueling map, depending on load, air temps, oil temps, etc.

When trims get too high, you'll get a CEL.

EDIT: Everything you posted looks normal...

Pick up this book http://www.amazon.com/Engine-Managem.../dp/1932494421

You will learn a LOT about tuning and be much more able to interpret sensor data

10-03-2014, 01:37 PM	#3 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 419	At idle and low load, it's going to hover around 14.7:1. On tip in, AFR might enrichen (or briefly skew lean, then enrichen, which I believe is what you found in 20% TPS to WOT), then move towards target (depends on load -- richer at moderate to high load). On throttle lift, fuel will cut, so it will read lean on coast down, returning to stoich as you approach idle. Anyway, unless you have changed the diameter of the MAF tubes from OEM, or have a sensor issue or vacuum leak, it should trim (without issue) to various targets in ECU fueling map, depending on load, air temps, oil temps, etc. When trims get too high, you'll get a CEL. EDIT: Everything you posted looks normal... Pick up this book http://www.amazon.com/Engine-Managem.../dp/1932494421 You will learn a LOT about tuning and be much more able to interpret sensor data GaleForce, zefaulter and olddudesrule like this. __________________ Enjoy it. Destroy it. Last edited by Jordo!; 10-03-2014 at 05:15 PM.

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