***Fuel Injector Kill Switch Wire Question***
 

I'd like to wire in a switch that will immediately kill power to the injectors.

1990 CRX HF:
Does anyone know what wire would be best to cut for an injector kill switch?

Photos show my "PGM-FI Main Relay"
http://i91.photobucket.com/albums/k2...F/DSC_0346.jpg

http://i91.photobucket.com/albums/k2...F/DSC_0344.jpg

Thank you,
~Jason

I put a FI kill switch in my '97 but I got to the needed wire under the hood.

But here's a thought, to help ID the wire on your relay connector there.

Examine the wires at the fuel injectors. 2 wires at each, and one of those is the same color at each injector. That is the 12V power wire. I think on my car they are yellow with a black stripe?? But you'll have to see it on yours.

The other injector wire is a different color at each injector, and that is the ground. The ground is the side of the circuit that the computer switches on/off to control injector pulses. That's why each one has it's own distinct ground wire. The 12V + wire is always powered when the engine is running.

Anyway, now you know what color is the injector +12V wire. Now find it at the relay. It splits to four wires later, but I think the color is the same. I'm pretty sure the system powers that wire ONLY when the engine is turning (including when starting cranking), and for a couple seconds after you first turn on the key - just to pressurize the system. So if you have a voltmeter, you can test to verify you have the right wire at the relay.

Good luck with it - it's a great mod to have on a FE car.

That's the best reply out of 3 sites: Thank you!
 

I just came across this. I'm only interested in killing power to the injectors. I need to keep my lights, signals and gauges. I want power killed to the injectors immediately...I don't want a kill switch to the fuel pump...I don't think...:rolleyes:

http://i44.photobucket.com/albums/f4...yschematic.gif

Thank you,
~Jason

Well I don't believe this will work. There is a red wire in some sort of configuration at each injector, but each red wire has a different color stripe. The remaining wire at each injector is either yellow, white or blue each with a different colored stripe. This is nuts...wiring always causes me fits! :confused:

just cut the PGM FI relays ground. Engine dies immediately. As soon as the ground is restored all turns back to normal, and a bump-start will fire you right back up. The temprary disruption to the fuel pump is not an issue. Use a push to open momentary then all you need to do is hold it while the engine dies. See my write up for a 5th gen civic your 4th gen will be quite similar.

Do I really want to cut the ground to the PGM FI relay?
 

Again I don't want to lose my instrumentation, lights, turn signals...

I appreciate the help guys...I'm trying to get this lined out today so I can drive it to work tomorrow. ;)

~Jason

Bestclimb has it. Cut the ground. That is what I did in my 1998 Civic. I do not lose lights, signals, speedo... radio... you name it and I'll tell you it still functions. What will happen is my UG will cut out sometimes, especially if I keep the switch off for an instant too long. But since it keep calculating, I believe the ECU has not cut out. Here is the build thread on my project.

Good luck.

james

Only thing you loose is the tach, but the engine is off so that hardly matters. Close the switch again and tach comes back.

Alright...I'm doing it.
 

I appreciate the help from you all. I'll try to get this done after work.

I'll take pictures and complete a write up when I'm done.

Thank you again,
~Jason