Kill Switch Shuts off my Ultraguage :(

[YolandaTheHonda]

Today I installed a kill switch in my 1998 Honda Civic DX. I used a "Push on/Push off Soft-feel Switch" that is rated at 3A at 125v so I'm not concerned about the switch. The switch interrupts the ground on the fuel injector relay on the passenger side to the right of the glovebox. The reason I decided to finally do this mod is that before to EOC I would have to get my key sequencing off and back on perfectly or the Ultraguage would shut off, sometimes losing the trip averages, or simply read error next to all the gauges on the screen. I don't understand why, but with this new kill switch I need to get the timing right as well. I need to push the switch back on the instant the engine comes to a stop, if pressed too soon the engine comes back to life, if to long after the UG shuts off or reads error.

I thought interrupting the injector relay ground wouldn't shut off any of the vehicles computers and I wouldn't have to deal with this problem anymore.

Any advice on why this might be happening? Has anyone run into this before? What would you recommend to fix the situation?

[YolandaTheHonda]

Is this the correct location for this post? Should I try a different area of the forums to get responses? any input is much appreciated.

[tvbd56]

I have no idea about the ultragauge but I have a scangauge and to keep it from turning off i switched the fuel type to hybrid instead of gasoline, so it'll still give me readings when the engine is off. Hopefully the ultragauge has something like that.

[dirtydave]

My scangauge does the same thing unless it kills the fuel pump and is set to hybrid. The injectors or ignition will make it give off crazy numbers.

[YolandaTheHonda]

Thanks for the replies. Unfortunately in reading the manual cover to cover I cannot find any settings to change from gas to hybrid. My understanding of the issue is that by hitting my kill switch and cutting the fuel injectors this is somehow telling the vehicle computer the ignition of the vehicle is off and the vehicle computer shuts down so the OBD2 shuts down as well, thus resulting in me losing data.

[Fat Charlie]

I subscribed but didn't answer because my Honda is different enough from yours that I wouldn't have anything helpful to add. When I tested my kill switch it didn't shut off the UG.

[YolandaTheHonda]

Charlie, how does your kill switch work? what circuit do you cut/interrupt?

[j12piprius]

My ultragauge used to go off when turning the key off at stop, but now it stays on.
Changes I've made include some of the following, from the latest ultragauge manual.

p44, read about pwr on detect, change it from 2 to 0;
p46, read about pwr off retries, maybe use if applicable;
p46, read KPW/9141 if applicable ~ my setting is 37;
p47, force mpg sensor, I'm using the MAP sensor on mine;
p47, injector cutoff, read and use if applicable.

[Fat Charlie]

Ignition coil.

[YolandaTheHonda]

John, Thanks for your post. It is incredibly helpful. Unfortunately I cannot test the settings that I changed until the drive to work tomorrow (car boxed in). But with a really quick test in the driveway it seems that the settings have helped alot. The gauge comes back on immediately after pressing the kill switch back on.

Charlie, I was under the impression that cutting the ignition coil does not completely stop the flow of fuel into the engine until it comes to a complete stop. Do you know if this is true? or possibly just misinformation?