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I have a project Idea...Need Input

Posted: Sat Jun 14, 2008 3:09 am
by zionzr2
I have an idea for a project that would be pretty electrically challenging as the way I see it. I need some input on how realistic, feasable, and cost effective this idea might be.I want to put in an engine kill/restart switch. The main purpose to this would be to limit idle time in traffic at red lights and such. This is an attempt to improve the in city fuel economy I get in the downtown area in which I commute. I know I could just turn the key anytime I want to do this now but would have to shift to neural to restart and turn the key again. I want to speed this process to a simple flip of a switch.The way I would want it to work would be a 2-way center return paddle switch that when you flip it one way it kills the engine and when you flip it the other way this would restart the engine.I would want to work only when the key is present and in the "ON" possition. It would also only work if the brake is being applied. (Not E-brake) It would also have to work no matter what gear position Auto-tranny is in.I would appreciate your thoughts and inputs on how this can be accomplished.As Always Thanks

Posted: Sat Jun 14, 2008 3:27 am
by northvibe
sounds like a microcontroller would need to be made connected to the ignition wiring harness and any other parts that need to be involved. I think having it start while in gear is going to make this difficult and maybe unsafe? I think your better off doing it the stock way, imo.

Re: I have a project Idea...Need Input (zionzr2)

Posted: Sat Jun 14, 2008 10:32 am
by mixer
Interesting idea, but I would have to say the savings would not be beneficial enough compaired to the safety issues as well as the potential damge to your vehicle. I have installed several remote starters on both manual and automatic transmission vehicles. There are ways to bypass neutral safety switch although I don't recommend it, and I always had the owner sign a waiver regarding their use/operation of the vehicle with this modification. If all your wanting is to save money/fuel I would recommend going to a reuputable shop and getting a good tune-up,and maintain correct air pressure in the tires. Otherwise good luck on your venture.

Posted: Sat Jun 14, 2008 11:01 am
by zionzr2
so would it be safer and easier if I pop it in neutral before fliping the restart?

Re: (zionzr2)

Posted: Sat Jun 14, 2008 5:14 pm
by mixer
If using your idea then I would say yes. I live in rural Ohio (Zanesville) so traffic isn't that heavy to where it wouldn't be worth all the effort to modify a system like this. I also run a CAI system on my 04 Vibe which I feel helps, moreso on the open road then in the city. Again, good luck.

Re: I have a project Idea...Need Input (zionzr2)

Posted: Sun Jun 15, 2008 12:27 am
by joatmon
I probably wouldn't do it to my car, but I don't sit idling at lights long enough to see any benefit. Also, I disavow any liability form anyone who tries this, and I also offer no guarantee that it will work as intended.I attached the starting circuit diagramAssuming you do not have the factory security system, then normally what happens is when you turn the ignition switch to start, 12V is connected through the park/neutral switch, which works it's way back to the starter relay, closing that relay which kicks on the starter. If you just put 12V to the starter relay (where the diagram marks it as ST Relay pin #1), the relay will close and turn on the starter, bypassing the ignition switch and the park/neutral start switch.When you step on the brakes, it closes the brake light switch and applies 12V to the brake lights. You could tap off that signal, and run it through your paddle switch to the starter relay. So, step on the brakes to get 12V, push the paddle switch to apply that brake light 12V to the starter relay. That is very basic, and doesn't require any sophisticated parts, just a switch and some wire taps. It might be better to also use the signal that tells the DRL module that the car is running, so that you don't accidentally engage the starter when the engine is already running. There's no interlock to keep you from turning the key to start the car when it is already running, but it might be an important featrure depending on how likely it may be that you'd accidentally bump the xwitch, or not notice that the engine was already running. That might take a relay, so that the circuit was only closed when the engine wasn't running.I don't know about the kill switch though, someone here has to have wired up a kill switch somewhere.The brake switch will only tell that the brake pedal is pressed, but not how hard. It might be possible that only lightly stepping on the brakes would be enough to allow the new start circuit to work, but not enage the brakes enough to hold the car in position when the starter motor engages. If you do it, be careful. I also don't know how repeatedly starting in gear will affect the starter. Obviously, the starter will have a harder time turning over the engine when it is in gear than when in neutral. There haven't been a lot of starter failures reported here yet, so the things appear to be fairly durable. but you might wear yours out earlier.

Attached files 013ss.pdf (30.3 KB)