I know that one can shift into neutral (racing the engine), but what kind of simple device, commercial or otherwise, is availble to kill the engine if a "runaway" begins to happen?

Thanks.

 

Been reading about Toyotas, huh?

Ignition switch - turn off the key. But not quite far enough to lock the steering column.

Start/Stop button in your toyota. But I guess you have to press & hold for 2 or 3 seconds if the car is in motion. That's an awfully long time when your car is racing down the highway.

It's tempting to say that EVERY CAR on the road today has brakes that out-class it's engine. But when the throttle is wide-open, you get little vacuum-assist and the brakes don't hardly work the way you expect. You REALLY have to STAND on them.

If you want to install a physical switch, I guess I'd go to the ignition switch & interrupt the one circuit that powers the ignition & main-relay.

 

Thanks, Jim!

 

If you want a kill switch you add a powered switch to the fuel pump. Did this to my boys civic back in the day.

Pop the back seat off...find the 2 wires running to the fuel pump CUT the positive wire. Then wire your powered switch to it and your done. I hid his switch for him so no1 could start his car unless they knew where it was.

 

That's another great idea. I had thought of this myself, but I'm not sure if the engine cuts out instantly, or does it go chugging down the road for some distance while the fuel system "drains". Any thoughts on that?

 

This article came out last week about the Toyota recall and the NHTSA findings.

businessweek.com/news/2011-02-08/runaway-toyotas-cleared-by-u-s-of-electronic-flaws.html

 

I’m not all that sure since I never cut his civic off with the switch while running. That will cause the engine to run VERY lean...when that happens bad stuff fallows

 

Yes, I saw that same news reported elsewhere.

I'm one of those "better safe than sorry" people. I also think it would be nice to have a convenient switch that would make it even more difficult to steal the car (although I can't imagine how anyone would steal our Lexus).

 

Tony honestly I would scrap the idea. If your trying to imitate what Toyota is doing...I see a fail. For one my dad works for yota...it's not just a switch that kills the dizzy. It's all integrated into the ECU (computer/ not sure what Toyota calls the computers)
With doing this to a Honda...not sure what year you are trying to do this with...But when I did this for my boy I did it cus he wanted "safety" well if anyone know a thing are 2 about stealing cars...if you want the car bad enough you know how to steel it weather it has a kill switch or a alarm system...there is always ways around it. ALWAYS

But what your trying to do if for...I see huge FAILL.

1. If you kill a fuel pump switch while driving you will cause the engine to run lean...maybe even kill your piston rings while at it

2. Vacuum purpose...if you kill the engine while driving...you have no vacuum pressure for breaks...can cause a wreck by not stopping fast enough or not stopping at all...even maybe locking your breaks up completely.

3. (might not be as important as the 1st 2 but still...) Rear engine mounts run on vacuum (if auto)...if no vacuum then well the mount "bottoms out" while there is no pressure in the line. Can cause the mount to fail much much sooner than it should.

..Just something’s to think about.

 

Not sure about this, but a couple things to think about...

1 - Lean causing too-high combustion temperatures. That's only within a narrow window of mixtures. Combustion temperatures get cold real quickly once it gets leaner yet. Probably happens within 2 or 3 engine revolutions if you switch off the fuel pump. Seems like damage to the rings would be from killing the spark while keeping fuel going.

2 - YES. The brakes will work properly, but they'll need A WHOLE LOT of muscle. I bet you won't be prepared for how much muscle it takes to stop. But that's ONLY if the throttle is wide open. If the throttle is closed, the vacuum will work OK because the car's momentum will be spinning the engine. I think that's true even with an automatic (in spite of risking damage to the trans).

3 - Actually, I think you apply vacuum to make the mount go SOFT. So if there's no vacuum, the mount will stay in it's hard state.

Kill switches are required for some racing, but that's to allow rescue workers to kill the fuel pump after a rollover or a crash.