A Kill the engine and coast button

[steve0701]

Ignition switches are expensive when they wear out from overuse, so if a person wanted to install a push-button to break an electric circuit and kill the engine what are some circuits they could tap into? How about the wire from the fuse box to the fuel injectors? The proper solution should not generate maintenance codes or cause engine damage. (Naturally, no one should ever coast if they have an automatic transmission or anywhere coasting is prohibited by law).

[dkjones96]

Your best bet is to put a switch that interrupts the main EFI relay. That'll kill any engine without setting a code.

[theholycow]

This is a common question.

http://www.google.com/search?q=site:...rg+kill+switch

[steve0701]

Originally Posted by theholycow

This is a common question.

http://www.google.com/search?q=site:...rg+kill+switch

Wow! You weren't kidding, it IS a common question. Thanks for your patience and consideration. So, I will be putting a switch before the EFI relay on my 2002 Civic, but I am not entirely clear on what happens when the power is restored. If the engine magically starts, I'd want to use a rocker switch to keep the power off as long as necessary. On the other hand, if a bump or the starter motor is always required for restart, then a momentary push-button switch would be better: just reach for the switch one time, not twice.

[theholycow]

The momentary switch will work fine. The engine won't restart without something to turn it, either the starter or a bump start. What kind of car do you have? My VW takes forever to spin down if it was at 3000 rpm (70mph in 5th) and if I turn it back to "On" too soon it's still spinning and resumes running.

[steve0701]

Originally Posted by theholycow

The momentary switch will work fine. The engine won't restart without something to turn it, either the starter or a bump start. What kind of car do you have? My VW takes forever to spin down if it was at 3000 rpm (70mph in 5th) and if I turn it back to "On" too soon it's still spinning and resumes running.

As I alluded while you were composing, it's a 2002 Civic LX. I don't know if it's harmful to kill the engine at cruising RPM, so I always give it 3 or 4 seconds to spin down to idle before I turn the key off and on. I used to drive a '69 VW Beetle which had exactly 2 pollution controls: a vapor return and a vacuum powered throttle positioner attatched to the carb linkage. It's sole purpose was to keep the available fuel burning for a couple seconds when you lift your foot, so as to avoid blowing poorly burned gas out the tailpipe. My repair bible encouraged people to disconnect it, since they were unreliable.