O2 switching question
04-11-2006, 10:19 PM
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O2 switching question Looking for suggestions on how to correct O2 errors. BTW, all logging was done in SD, with MAF disconnected.
When not switching correctly, they:
1) have a square wave (hang too long at top or bottom) which results in surging or eratic lean/rich values
2) Hang at >900 and don't move. This happens at various RPMs, typically idle and other places.
For the hanging issue (stay at 900+) I'm thinking they need more fuel to switch, or I could adjust the VE table. Any other ideas? I'm torn between adjusting VE table and fueling (IFR, pulse width, etc.) tables.
BTW, the car is SC, so both the VE and IFRs (upgraded to 42# injectors) are probably a bit off.
When not switching correctly, they:
1) have a square wave (hang too long at top or bottom) which results in surging or eratic lean/rich values
2) Hang at >900 and don't move. This happens at various RPMs, typically idle and other places.
For the hanging issue (stay at 900+) I'm thinking they need more fuel to switch, or I could adjust the VE table. Any other ideas? I'm torn between adjusting VE table and fueling (IFR, pulse width, etc.) tables.
BTW, the car is SC, so both the VE and IFRs (upgraded to 42# injectors) are probably a bit off.
04-11-2006, 11:59 PM
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To switch low you need less fuel.
To switch faster you need to overtravel less, in the
fuel dithering that is done to make switching signal
and get the sensors hotter. Cold is slow.
Be sure you are not simply seeing open loop, enrichment
active at idle. Boosted with the added drag torque
maybe you are wandering into PE just sitting there.
Log your fuel air multiplier, see if it is a mystery or
just mistaken intention when the O2s peg high. That
is only someplace you can get with fuel and heat,
or an electrical fault (unlikely).
To switch faster you need to overtravel less, in the
fuel dithering that is done to make switching signal
and get the sensors hotter. Cold is slow.
Be sure you are not simply seeing open loop, enrichment
active at idle. Boosted with the added drag torque
maybe you are wandering into PE just sitting there.
Log your fuel air multiplier, see if it is a mystery or
just mistaken intention when the O2s peg high. That
is only someplace you can get with fuel and heat,
or an electrical fault (unlikely).