snatch

Ok, I swapped my D16Y7 tranny for a Y8 two weekends ago. No problems during or after, except for having to let it run a little to get all the air pockets out of the cooling system and refilling it again. I also left the IAT sensor unplugged for half a day, but have since plugged it in and reset the ECU (by unplugging it for a few hours).

Now, I will admit I have a ricer narrowband A/F gauge hooked up that I've had for a few years, just a great light show more than anything. Before I did the swap it would go rich under WOT, at idle initially then back and forth, and for the first few minutes after startup. Lean if I let off the gas while coming to a stop but didn't push in the clutch, and going back and forth as they normally do when just cruising at a steady speed.

Now, since the swap, it runs rich for the first 15 seconds after startup or so, that's it. Otherwise it's lean, usually off the gauge lean. At WOT I would be lucky to get at transition point from lean to stoich, but never rich. When driving at a constant speed it is off the gauge lean, all the time.

Now I know these gauges are not considered accurate, and that's not my concern. My concern, or curiosity, is the difference from how it was before. Why after a swap involving mechanical parts, does something electrical act different? All connections appear good, they are soldered and shrink wrapped.

ECU is stock DX, I/H/E, EX tranny obviously, that sums up the engine mods.
There are no CEL's and the car feels and drives perfectly fine.

Any ideas why this is happening?

Thanks.

snatch

In addition, if the connection was intermittently bad at the O2 sensor wiring, wouldn't the gauge read all the way on the rich side when the connection was poor, then give a reading when the connection was good? IIRC when the gauge has no signal it reads rich.

zeroice

shorter gears might have somthing to do with it not sure, however as far as not having a good connection you are right it will read rich all the time and stay like that.

snatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zeroice &raquo;</TD></TR><TR><TD CLASS="quote">shorter gears might have somthing to do with it not sure, </TD></TR></TABLE>


How would a mechanical difference such as different gear ratios affect the O2 sensor and ECU's closed loop process of maintaining an A/F ratio?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zeroice &raquo;</TD></TR><TR><TD CLASS="quote">however as far as not having a good connection you are right it will read rich all the time and stay like that.</TD></TR></TABLE>

This is what I thought.

stevel

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ****** &raquo;</TD></TR><TR><TD CLASS="quote">How would a mechanical difference such as different gear ratios affect the O2 sensor and ECU's closed loop process of maintaining an A/F ratio?

This is what I thought.</TD></TR></TABLE>

there is a correction factor for each gear in the ecu for the fuel map. Now that the gear ratios are different, that correction factor doesn't match the gear it's in. That's the only thing i can think of.

s

2k.civic.si

"ricer narrowband A/F gauge" theres your problem...its not accurate in the first place

postman

the gauges are more acc. than some people think. there not 100% but better than what people dog them to be. if you had a dvom on the o2 you would see the same as the gauge.

snatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevel &raquo;</TD></TR><TR><TD CLASS="quote">

there is a correction factor for each gear in the ecu for the fuel map. Now that the gear ratios are different, that correction factor doesn't match the gear it's in. That's the only thing i can think of.

s</TD></TR></TABLE>

So the only way to correct this is run the correct ECU from a EX 5 speed.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2k.civic.si &raquo;</TD></TR><TR><TD CLASS="quote">"ricer narrowband A/F gauge" theres your problem...its not accurate in the first place</TD></TR></TABLE>

As previously stated, I'm not concerned so much about the accuracy of the gauge itself, more so the difference between now and 2 weeks ago. There is a difference between accuracy and precision. I'm concerned/curious about precision.