Injector kill switch?
 

I want to know if anyone has a link to injector kill switch schematics. Do you just tap the 4 power wires, one from each injector, wire it back to a switch, ground the switch, and have ON/OFF?

I'm not very electronically experienced, but really want to be able to EOC w/o ruining my starter/ignition parts. It's just too much trouble to EOC w/ an automatic w/o the kill switch, so I really want to incorporate this into my mods.

Thanks,

John

You'll still have to use the starter to get the engine going again. The only thing having an injector kill switch will do is let you kill the fuel supply, you go into neutral the engine will still come to a stop and you won't be able to get it back into gear without starting the engine again first.

The injectors on my GMC and VW have a single common ground wire, it might be easier to interrupt that one wire than all 4 power wires.

I haven't installed it yet but my plan was just to interrupt the ground wire since they all have a common ground but have individual power wires.

I just got a regularly closed button switch and figured I'd wire it inline. This simply is a closed connection all the time and if the button is held down it breaks the ground and opens the connection (note it's not actually a switch, letting go closes the connection again). So I figured I'd hold it for a couple seconds and let go and be ready for pop starting.

Ah shiat, I for some reason or another, was thinking I could just kill the injectors in neutral and the coils would still be firing and then I could just restart the injectors after a nice glide.... this isn't accurate?

darn automatics...

Yeah, the coils will still fire, but without fuel, and in Neutral the wheels won't spin the engine so it would stall rather quickly. The point of an injector kill switch is to manually induce DFCO to keep the engine running without restarting. Otherwise you're just doing EOC.

-Jay

i put one of those in my aspire. idling in the driveway i could kill the engine, but on a coast downhill holding the button/switch never prevented me from pop starting and taking off again. you DO stumble a bit so i would only practice this with plenty of room for the engine to return to normal fuel supply operation. i was going to put the circuit on a vacuum switch so when i let off throttle it would do it on its own to induce dfco but i have been lazy and never purchased the vacuum switch.

So what I'm gathering is w/o a manual transmission, this is a no-no.

???

For an automatic I'd recommend also having a switch to manually override torque converter locking and control it manually. Maybe even use a DPDT switch that locks the TC while the injectors are being cutoff. IDK, but its a thought.

-Jay

With an automatic transmission it's still useful, but not for EOC; it's just good for forced DFCO. You would have to leave it in gear and remember to turn fuel back on before your RPM gets too low.

Default Re: Approaching 50 mpg. Share some thoughts?
andmara -

Quote:
Originally Posted by andmara View Post
...

Car mods, not in any particular order:
Kenda tires that are rated at their maximum load at 44 psi. I have them pumped up to 55 psi. Magnaflow 'straight through' muffler. You can look in one end and see daylight in the other. It eliminates pumping losses on the going out end. I have switched the DRL's (Daytime Runniing Lights) so I can turn them off. I have switched the alternator so I can turn it off also, (THAT was a trick finding the wire(s) for that!) and have installed a volt meter so I can see what the battery is doing.
Can you document this mod in detail in this or another thread?

Quote:
I have discovered that I can make my complete daily commute in daylight, without the heater fan, without running the alternator at all. I hook the car up to a battery charger at night. In fact, my next step is to install the battery charger in the trunk and just leave a plug hanging out the front so I can plug it in at night. I installed a 'kill switch' next to the gearshift lever so I can shut the engine off easily whenever I want to. I made a mistake, though, and interrupted the signal going to the ignition coil. What I didn't think about is that the fuel injectors are still delivering 'idle level' quantities of fuel so once the engine is warm, is 'diesels' badly when you shut off the ignition. I think I'm going to have to interrupt the power to the PCM with my kill switch instead.
Hmmm.... what else..... I'm kind of ashamed to admit it, but I also don't have an air filter on it. I took it off last weekend when I was trying to figure out where to set up a ram air configuration and haven't put it back on yet. I kind of like the sucking sound!
I bought a used Zeitronix ZT-2 on Ebay last week and I'm going to use my laptop to lean out the Air/Fuel mixture. I think this is the thing that will put me over 50 mpg.
I guess that's about it for now.

Regards,
Mark
Here is a variation on the kill switch :

self inflicted high idle - 06-28-2007
https://www.saturnfans.com/forums/sho...83&postcount=1
Quote:
I wondered if anyone has a better solution for this issue.

I (and others) will coast with the engine off on a saturn sw2 using a "kill switch" in line with the FI fuse. After restarting it, it wants to idle at 2000ish rpm! I presume it was trying to bring the idle up with the engine not running, but it doesn't help my mpg goals for it to race around at 2000 for 5 or so seconds.

For now, I just unplugged the solenoid after it settled down to a 900ish rpm, but of course cold idle/AC idle stumbles a bit. I don't spend hardly any time idling or with the AC on, so no biggie, I just wondered if there was a better way than issuing a peace bond to the computer over control of the idle speed.
The kill switch is the fuel injector fuse (10 Amp, labelled "inj" in the engine bay fusebox) through a relay and momentary off switch. skewbe didn't report the problems you are describing, just bump-start and go.

CarloSW2



just did daytime running switch today,,,

i'd want to switch to 0w-30 before trying this...not even sure if it is worth doing, anyone have an opinion?