Help me AEU86, you're my only hope

[jondee86]

(03-24-2021 01:06 AM)totta Crolla Wrote:  I don't think it is necessary to sink money into a wideband system...

With all due respect, I would suggest that a WBO2 gauge and sensor
would be a good investment both for tuning and trouble shooting.

A narrow band sensor is fine for a stock engine with an OEM ECU that is set
up to work with a narrow band sensor. The "switch-like" output of the sensor
hovers around 0.5V. When it is above 0.5 the ECU reduces fuel and when it
is below 0.5 the ECU adds fuel. The sensor reacts to the change in fueling
so that the up-down-up-down cycle repeats over and over. I believe this
can happen several times a second.

The problem with the narrow band sensor is that it can not tell you HOW
rich or HOW lean the mixture is. Enter the wide band sensor that has a more
gradual change in output so that it can be scaled to read from very rich to
very lean. When used in conjunction with a compatible WBO2 controller and
gauge, you can see on the gauge if you are at 17:1 or 12:1 and how the
reading changes with load and rpm.

Most WBO2 controllers can output a simulated narrow band signal for feeding
to a factory ECU designed to work with a narrow band input. But your gauge
will be telling you the actual AFR under all operating conditions. Down the
track if you upgrade to an aftermarket ECU the wide band signal can be fed
directly to the ECU for automatic or semi-automatic tuning of the fuel map.

Incidentally, narrow band sensors are installed close to the head for
maximum heating while wide band sensors usually get installed a bit further
downstream in the collector to avoid overheating.

Cheers... jondee86

PS: And while I've got you here, I'd suggest that you forget about trying to
make the narrow band happy and start working on possible mechanical
issues. For example... is the TVIS system working correctly ? If the TVIS
plates stay closed (don't open around 4200rpm) you will have good low rpm
operation but be short of breath at high rpm.

Pulling the hose off the MAP sensor should cause a rough idle... maybe need
you to play with the throttle to keep it running, and blow a bit of black
smoke/smell gasoline in the exhaust.