Is this the Civic inj. power wire?

[brucepick]

'97 Civic HX (Gen. 6).
I'm looking for the fuel injector power lead, a single wire for all injectors. Harness at injectors has individual wires for each cylinder so I don't want to cut all of them. This is for a fuel cut for EOC.

[EDIT]:
The +12V power to injectors is continuous when ign. is on. The grounds are individually controlled per injector. So my plan is to cut the +12V early in the circuit where it is still 1 wire for all 4 injectors. At the inj. rail it is 4 wires, all the same yellow+black color code. [/EDIT]

Found this 10-pin connector at drivers side fender, near firewall. Has a single very heavy black/yellow wire at bottom corner, both sides of connector. Is that it??

[daring4]

Hey check to see if you have injector fuses first. It will save cutting up your harness, I put inline fuses and a switch on my car to kill the injectors. Mine is a v6 and one fuse for each bank of cylinders, yours may only have one fuse if its a four.

[Old Tele man]

...BEFORE you cut into anything, did you consult the factory schematic to see what the "color-code" is for the wire(s) you're after?

...and, here's a "tip"--instead of cutting thru any insulation, simply solder the signal-wire to a hefty straight pin and simply stick the pin thru the insulation and tightly wrap the area with electrical tape (about ½-inch on either side).

*** DO NOT stick the pin thru the wire from top to bottom; rather, slide the pin under the insulation like the nurses do the needles when you give blood.

[brucepick]

Originally Posted by daring4

Hey check to see if you have injector fuses first. It will save cutting up your harness, I put inline fuses and a switch on my car to kill the injectors. Mine is a v6 and one fuse for each bank of cylinders, yours may only have one fuse if its a four.

My Haynes manual says no fuse specifically for the injectors. 15A fuse #44 supplies power into the main relay. If I cut at that fuse that would also disable some other stuff managed by that relay, not just injectors. That is, fuel pump plus four wires to/from the computer.

Output from the main relay is to a connector that splits three ways, one goes to the injectors. If I can find that connector I could cut the power to injectors there. Anybody know where the connector is? I think I gotta crawl under the dash.

I suspect the connector I found in photo (drivers side fender) is not the place to go - the yellow + black wire there is very heavy; doesn't seem appropriate for the job it would do.

[brucepick]

Originally Posted by Old Tele man

...BEFORE you cut into anything, did you consult the factory schematic to see what the "color-code" is for the wire(s) you're after?

...and, here's a "tip"--instead of cutting thru any insulation, simply solder the wire to a hefty straight pin and simply stick the pin thru the insulation and tightly wrap the area with electrical tape (about ½-inch on either side).

*** DO NOT stick the pin thru the wire from top to bottom; rather, slide the pin under the insulation like the nurses do the needles when you give blood.

I DO like the straight pin method - thanks for that. But I'm pretty sure it's not what I need for this. I need to cut the 12V line en route to the injectors, not tap into it.

I consulted the Haynes diagram. Shows the wire as yellow/black, which is what I do find at the injectors as +12V (constant when ign is "on"). Diagram shows a connector before the injectors where the single 12V wire from relay is split 5 ways: the 4 injectors and also one to the idle air control.

I do need to cut that wire back where it is one, not where it's a separate wire for each injector. I'll switch the severed wire at a good quality relay that's normally "on". When I send 12V to relay coil from a dash switch the relay will open the connection until I flip the dash switch back.

Come on, somebody must have wired up a good fuel cut switch for a Civic??

[SVOboy]

You could chase the wire back to the ECU and check an ECU pinout to be sure. Otherwise, you could depin the wire and see what happens, so you can avoid cutting.

[dcb]

Also, does anyone know if interrupting the cam or crankshaft sensor works on these engines? That is just a signal and doesn't require much of a microswitch to interrupt.

My metro liked the camshaft signal interrupt switch just fine
My saturn liked the crankshaft signal just fine.

On both it kills the injectors and the ignition so no extra fuel squirted, and no "dieseling" on any fuel remnants. It's the cleanest and quickest, once you figure out how to trick the computer into shutting off the injectors and ignition. Neither one throws any "codes", so I wondered if any honda folks have experimented with this approach.

I made sure they were both turning off by watching an inductive timing light and the gph reading on the guino while playing with the signal leads.

There are ways to kill both injection and ignition with a couple relays, but that may be complicating things.

[brucepick]

Originally Posted by SVOboy

You could chase the wire back to the ECU and check an ECU pinout to be sure. Otherwise, you could depin the wire and see what happens, so you can avoid cutting.

SVOboy - Next time I get outside I'll separate the connector that's in the photo - and check for continuity in the yellow/black wire out at the injectors.

dcb - I kinda think I'd like to keep the ignition firing. To burn off any fuel still remaining. Though there might be a benefit to killing that off too? I'm not sure where those sensors are but I suppose I could find them.

[dcb]

the problem I've had with leaving the ignition on is that it "stumbles", even on my multi-port saturn. So that I noticed a lot more accidental "relights" as you have to hold the kill switch in for longer, as the engine is stumbling along on a very non-stoich bit of fuel in a rather unpredictable manner.

It dies with authority if you kill the ignition
It doesn't inject another drop of fuel if you kill the injectors
So "ideally" you do both.

Also with the injectors stopped, you can add "forced DFCO" to your toolkit, once in a while it is handy to engine brake outside the pre-programmed DFCO parameters without using fuel.

[Christ]

ECU Pinout wire colors? - Honda-Tech

The CKP and CYP are the sensors that dcb was referring to. Their pinouts are on the B terminal clip on your ECU.