Is this the Civic inj. power wire?

[daring4]

I bet your fuel injection is more advanced than the old Fiero! All my injectors fire at the same time, yours are controlled independantly I assume.

[brucepick]

Found the inj. power wire.
It's in the connector in photo but not the fat yellow + black wire noted earlier.

It's yellow + black, the top position, center column (as shown in photo with connector clipped to bracket).

daring4, yes, I'm pretty sure the injectors are individually controlled both for timing and maybe also duration, attempting to adjust qty per cylinder to keep it smooth??

Now - from dcb's post, I'm reminded that cutting the 12V power to injectors will NOT be directly noticed as fuel cut by the 'Guino because it reads the ground side of the inj circuit. So after fuel cut the engine spins down for a second or so before stopping. So the Guino would read fuel use till the engine stops spinning at which time the computer stops firing the injectors via the ground-side circuit. That's when the Guino will recognize full fuel cut. Over a tankful I calculated that might be .04 gal which may or may not be "significant".

To get the Guino to read it properly, I'd need to either follow the notes to kill the input from those 2 sensors to the pcm - OR - cut the 12V injector power and at the same time, cut the injector signal to the Guino. That would require a 2nd relay running off the dash switch that will control fuel cut. I could handle that.

It's late. Work tomorrow. G'night.

[dcb]

I would wait till you are bit on the guino speculation If the injectors are not getting power then neither is the guino injector signal.

[daring4]

Brucepick I think the guino will stop seeing fuel use as soon as the signal to injectors is lost, regardless of engine rotation. When I flip my switch it goes to 999mpg instantly, and I have tried killing the injectors with the throttle pinned to keep the engine spinning...same result 999mpg. Doesn't coast very good that way FYI!

[brucepick]

Originally Posted by dcb

I would wait till you are bit on the guino speculation If the injectors are not getting power then neither is the guino injector signal.

dcb,

I'm sorry I don't get what you're saying about "wait till you are bit on the guino speculation". I'm sure I'm just being obtuse but hmmm??

BTW I do have the guino pretty well calibrated. Did distance with a GPS. Fuel qty is good enough now that a 9.4 gal fillup was only off by about .05 gal. I put in the correcion for that so hopefully next fillup will be even closer.

[dcb]

you are saying that the guino will keep tracking after the injectors are cut? that is the part I thought was speculation as it didn't make sense to me. If you are still getting a reading then they are probably still firing.

.05 gal out of 10 is better than a pointed stick in the eye

[brucepick]

OK I follow.
We'll see once it gets hooked up. Spent the evening doing the interior part of the project - lead from the engine bay and powered + wire hooked up to dash switch. Later for the engine bay side with relay.

[brucepick]

OK, it's hooked up and working smoothly.

The only issue is, when I kill the engine that way the computer behaves as if I'd keyed off the engine - in that it refuses to allow lean burn until driving exactly 2 miles with engine running. Unfortunately I'm not sure exactly where in the circuit I made the cut; only that it does kill the injector 12V power before it gets to the injectors.

Next time I work on it I could try the CKP and CYP sensors that dcb and Christ mentioned.

[PaleMelanesian]

Great! That should work just fine for me, since I have no lean burn.

[dcb]

@bruce, are you able to tell when in lean burn with the guino? by watching mpg or gph or something?