Just thinking out loud on o2's

[alpha-dog]

This is something that I won't do since I have my PSC1 working and I can control the A/F ratio. However, since I've been digging into this area quit a lot recently, one thing that stands out is how NB O2's work. They don't directly read the A/F ratio. In fact, they only read lean or rich. I think I read somewhere that a precat O2 will cycle 99 times a second. Just wondering if you took a Shane Jackson ZFF driver card and made sure that the PRF was under 100Hz ( like maybe 90 to 99Hz ). Then the duty cycle could provide a lean/rich condition. A 50% duty cycle might be equal to 14.7:1 A/F R. It may sound a little crazy but could a ZFF driver card emulate an O2 signal. For those guys with 2.5 vdc bias O2's, just let the driver signal ride on a 2.5vdc level. Just an idea, I don't really know what I'm talking about.
You might need to clamp the signal down to 1vdc also.

[Painless]

Even simpler, a sine wave generator could do it easily enough.

Only problem is the O2's don't *always* just fluctuate steadily. They read high when first started up and give steady readings on deceleration.

[alpha-dog]

I guess that's what a fuel map is for. It's to sophisticated for me. I was thinking of telling one lie to the computer. Also, that's why I think those voltage adders aren't working very well either.
The problem with a sine wave is you can't adjust the width of say the upper portion of the wave. It would alwas be 14.7:1

[Painless]

My own personal view on EFIE's .... they should only be used for making the ECU *think* it's at 14.7:1.

Everytime you tune a MAP / IAT / CTS or whatever sensor to change the A/F ratio, you should then re-visit the EFIE to ensure that the fuel trims are stable and within the normal range. First, we change the ratio, then we convince the ECU that we haven't.

The problem comes in that we can only go far before the ECU says 'pulse width is WAAAAY to small' and throws a DTC. It's at this point that we need to do things like lowering the fuel rail pressure and fooling it's sensor.

Russ.

[alpha-dog]

I'm installing a stand alone AFR meter tomorrow ( wideband ). I believe it will read lean once HHO is introduced. I'm going to record those first readings wilth HHO and then after the PCM richens itself up ( after a few days ) to adjust for the extra oxygen I'll set the AFR's to bring the AFR meter back to the recorded values. That should fool the PCM and operate at the correct air/fuel ratio.