Kill switch accomplished - Fuel Economy, Hypermiling, EcoModding News and Forum

homeworkhome53 · 08-03-2008, 10:04 PM

I found a fuse in a box in the engine compartment marked fuel which I jumpered around with an inline fuse and switch which I mounted beside the manual gear shift. Works fine, but I can still hear my fuel pump running when in the off position, so I went back and looked some more and found a relay that is marked fuel pump in the same compartment. I think what I'm killing is the fuel injectors. When I throw the switch the car continues to run for a few moments. Just long enough to take it out of gear before it loses power. The instrument cluster continues to run and the odometer continues to total which is what I was looking for. The lights stay on which was a biggy for night driving.

homeworkhome53

MetroMPG · 08-03-2008, 10:50 PM

Does it restart instantly? If you kill the fuel pump, it might have to repressurize before the car will start/run properly. Which could take a second or 2.

I interrupt my coil pickup signal from the distributor, and it still takes a heartbeat for the engine to stop running.

homeworkhome53 · 08-04-2008, 07:50 AM

The restart is instant as long as you reset the switch to on.

homewrokhome53

SVOboy · 08-04-2008, 01:06 PM

Interesting. I really need to get a kill switch going on my car, thanks for the inspiration,

cfg83 · 08-04-2008, 04:20 PM

homeworkhome53 -

What SVOboy said. I gotta get my act together on this one.

CarloSW2

getnpsi · 08-04-2008, 04:42 PM

Is this kill for coasting or theft protection? It's a bad idea to kill the fuel pump. If you are in a dangerous situation it takes a few key cycles to get going again and it could kill you.

whokilledthejams · 08-04-2008, 08:45 PM

I agree that not killing the fuel pump is probably ideal, actually. The faster you can restart the car when the need arises, the better.

I need to get a kill (and starting) switch, too. I have a relay laying around, and wiring diagrams, I'm just not sure what kind of current I'd need to deal with as far as selecting my switches. I suspect that I'm not dealing with anything serious if I go through the ignition circuit, but I am having a hard time finding a straight answer. I'm getting more brave, within the context of limiting it to backroads, with my EOC'ing, but switches would make it simpler.

bbjsw10 · 08-04-2008, 10:05 PM

Here is a write up I did on a metro kill switch but should be able to make it work for a lot more cars. It works really well restarts as soon as I let off button and bump start or crank it over.

Kill switch how-to

ajax_6531 · 08-08-2008, 05:57 AM

does anyone have the schematics to a jetski? Those have built in kill switches. You might find what they use to kill it would benefit us here. Of course, I could be talking out of my a$$.

The Atomic Ass · 10-14-2008, 06:10 AM

Quote:

Originally Posted by ajax_6531

does anyone have the schematics to a jetski? Those have built in kill switches. You might find what they use to kill it would benefit us here. Of course, I could be talking out of my a$$.

Jetskis, (and motorcycles, and similar vehicles with kill switches built in to an FI system), have a safety loop, that when broken, stops the computer. On my Burgman in particular, this loop goes through the kill switch, side stand switch, and tip-over sensor.

Cars don't have this loop, so the same principles don't apply, unfortunately.

On this note, however, I'm looking at getting a Subaru Outback, anyone know how well their computers deal with having the injector power cut?