Engine off coasting on my matrix

[Weather Spotter]

What amp rated switch will I need for that job? I like the idea of a NC switch. I was planning to make my splice a few inches out from the connector presuming I can find the right one. Any idea how to find that connection from the others in the area?

[Niner]

Originally Posted by Daox

It looks like all of your injectors splice together at junction l12.

Don't junctions happen inside wire bundles? I could not figure out how they worked in my xA.

There is another option - the single black wire/white stripe coming from the ignition switch goes through pin 8 of connector IG1. This is located in the same place as the splice - it's a 10 pin connector with two large central pins - one of those is #8. The male/female end connectors can be seen on page 8 of the connector diagram. You should be able to get to it by popping out the glove box.

[Weather Spotter]

so option #2 is put a NC switch in line with the black/white pin 8 wire? What else will this kill? would it not be the same as turning the switch?

[Niner]

No, the only thing that is connected at the #8 pin is the keyswitch to the injectors. Nothing else will be killed.

Also, if you decide on the relay, here's how to wire it. You can run a very light gauge of wire from the relay to your switch (and then ground). I also used a male and female disconnect to hook to the relay I used, so that I can pull it out and plug them back together if I take it back to the Toyota dealer.

[Weather Spotter]

Niner: thanks for the ideas

I like the idea of making it non noticeable at the dealer, I will have to take my car in some time in the next few months to get a free ECU replacement (recall). I think I will get enough flack about my car without the kill switch. Taking it back to stock (as far as the kill switch) in the parking lot is a big +.

Why bother with the relay though? That wire looks to be low current as it is tripping a relay itself. All I would need to do is to find that wire, add a NC switch and route it back to the splice point. If I hide the splice the dealer should never see it

[Niner]

I think you're following the wrong black/white wire. From the ignition switch going right, take the upper black/white wire. That goes through a little square box labeled 8(IG1) and then breaks into 4 wires (passing through octogons that represent junctions), and then into devices that look like little coils (the injectors), and then into the ECU.

The boxes that also hook into the other black/white wire are the spark ignitors. Those do have an internal relay, so they will be pretty low power, but you'd still be spraying gas into the engine until the ECU figured something was wrong.

However, you could use a normally closed switch for the injectors. They're not terribly high current - the wire appeared to be 16 or 18 GA, but current across that wire could go up to a few amps. I'm using a microswitch that's rated in hundreds of milliamps because I couldn't find an NC switch at the local Radio Shack above 1 amp. Of course, if you order online, finding something the right size or oversized should be easy.

[Weather Spotter]

Thanks for the correction I was looking at the wrong wire. We are still talking about cutting the injectors just past the I12 junction. I will have to go looking for switches, might an auto parts store have a better selection? What amp rating should I get? Would a 10A be enough for a direct splice?

How big is your micro switch? I like the mount point and might use it if I can find a switch to fit

[Niner]

I was talking about the#8 pin on the IG1 connector (plug and socket inline in the wire), Daox was talking about the I12 junction, which is nearby but I think actually is within the wire loom. Either way, it's the same single wire.

10 amps should be enough. I am running a 10 amp relay because it was cheaper than the standard 30 or 40 amp auto relay. Looking online, it seems like most stock injectors are "high impedence", around 12 or more ohms, so 1 amp - so I would be comfortable with 3 amp rated switches. I looked at Autozone and found even less good switches - just large toggle switches and a few momentary-on switches. Nothing at all was normally closed.

The microswitch I got at Radio Shack in a 4-pack (I possibly plan on using the other three to place dash buttons for my MPGuino, which is far back on the dash). The size of the little box is 6mm x 6mm x 4mm, with a button that is 6mm high and 3mm diameter. There are 4 little legs on the bottom, each about 2mm long. If you get something similar, make sure to check with a multimeter which pairs are connected and which are open - it was not the way I expected. It looks like of like a squashed animal (legs out to the side) so I guessed that it was either two switches, left to right, or two contacts for one switch, left to right. It ended up being two contacts for one switch that connected front legs to back legs.

[Weather Spotter]

I will have to go shopping for more modding supplys

After some reading I think I understand how to hook this up!
If I do it with a NC relay, I would only need a NO momentary switch right?

I like the little bump switch on the stick. How did you attach it? Any more picts then here:
http://ecomodder.com/forum/showthrea...-xa-14767.html

[Niner]

No more pics, but there's not much more to show.

When I pulled the shifter off the car, I saw that the lower part had a good sized gap between the cover and the actual shifter rod. I drilled a hole well oversized for the button, and then took a Dremel and shaved a groove to help hold the base of the button (the sidewall was a little too thick for the button to reach through).

To make the button, I got some perforated board at Radio Shack - it's got a regular grid of holes and copper rings around each hole. I soldered the 4 corners of the button to a 1/2" x 3/4" scrap, and then pushed the wires through the backside of the right two holes and soldered them to the contacts. I put the button in place, mixed up a little epoxy, and glued it down. Afterwords, I also stuck a little electrical tape to prevent any shorts from the rod, since shorting to ground would kill my engine.

The way the shifter is mounted goes like this: there is the rod, and a plastic clip set in a groove on the rod. The shift boot has a ring that sits on top of that clip, and the shifter top screws down until it's clamping the boot against the clip. What I did was pull the boot away from the center console, broke a little bit off the clip, and put a hole in the boot so that as I spun the shifter cover on, all three pieces could spin around with the wire. Then once the shifter was where I wanted it, I attached the wire to my lead coming from the relay, and put a screw into the floor for the other side of the switch. Then clip the boot back onto the console, and you're done.