Donerstude
New member
After reading the roughly two years of this thread, I have to say Kball your a saint for sending pm's to all, and I thank you! Can I get the Pm when you have a chance? Thanks again.
Where do I install a fuel pump Kill Switch?
- Thread starter GVL
- Start date
pluton
Senior Member
Thank your brother on behalf of everyone here.
I favor the simple in-line switch, because I don't need to use it most of the time...only in certain neighborhoods.
To add an extra motion or activity to be necessary in order to normally start the car every time I start it would be going in the wrong direction for me.
Well you can always have the switch on ON but turn it off when you feel the need
kball
New member
10 amps or better should be fine.
Thanks bud. You helped me a lot
pluton
Senior Member
Precisely. On my previous vehicle, that's the way I worked it.
gamefreakgc
Elite Member
It's better to install a relay, and then have a switched ground instead. Most automotive relays are 30 amps or higher. That way if your welds are iffy you won't have your fuel pump die on you in the middle of nowhere.
Yes maybe. But... Does the fuel pump even run of a relay ? Look at the wire your cutting. It's thin!
TheDurk
Elite Member
That wire KBall uses is controlled by a relay (the so-called Circuit Opening Relay). Rather than put in an extra relay which strikes me as a rather inelegant daisy chain with attendant reliability issues, just install the switch on the coil side of the relay if you feel strongly about it. There at least a dozen ways I can think of to do this--there is no reason to have to install another relay in the truck. But your point is valid--I'm pretty sure that's a 14AWG wire--any decent switch can handle the load on it. 10 AMP or better should be just fine.
My thought is that if you are messing with a critical system like this, the simpler the better. Using the AC switch as one guy did is a perfectly acceptable high reliability way to do it (as long as it is US made Leviton or Eagle, not some Chinese POS--those have a cycle life of about a year even with zero current.)
BoomStick's brother's circuit is elegant and functional and exactly why you never ask an engineer how to do anything. Just too complex. Too much to fail. KISS is the operative principle.
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I agree. And thumbs up on leviton or eagle.
Quick question. When the switches is installed. And your testing it. For example, having the switch OFF, which the fuel pump is OFF, and you start the engine and let it run for little and it dies because of no gas. Is that ok or can that be bad for engine. And then obviously after you see that it works, turn the switch ON and let it pump fuel and start the car.
gamefreakgc
Elite Member
I forgot about the COR. The last kill switch I installed was off the actual fuel pump wiring, not a relay so I made sure I didn't fry my switch by adding a relay. That fuel pump can carry a decent amp load at times.
With these newer 4Runners there's so many electronics and fuses, there's a number of ones you can pull or take out to keep the engine from starting. I haven't needed to install a kill switch since I just pull a vital connection and it's dead. Your average crack-head thief isn't going to look through every fuse box and inspect, then go to a parts store and buy a replacement fuse/relay lol.
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Can't imagine that much amps going through a 14g wire though. [MENTION=44978]kball[/MENTION] has been using a simple switch and all good
TheDurk
Elite Member
You may set a P0171 by cutting the fuel pump. It should clear itself with no lasting ill effects. Or you can do a clear by unplugging the EFI fuse if it doesn't, or use a scanner to do it. Fuel-injected BMWs of a certain age needed to be bled to restart after a fuel cut, but I have not heard this of our engines. If a thief insisted on cranking and cranking with no fuel, you might get to that point. I don't know. At the end of the day, it's less bad than running out of gas, which sucks crud from the bottom of the tank, but is otherwise the same as far as the engine is concerned.
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pluton
Senior Member
Why would you ever, EVER cut the power to the fuel pump wire while it is energized? Right...you wouldn't...that's what I thought!
TheDurk
Elite Member
Actually, no one proposed that. The fuel pump was never energized in the question asked. The power feed was cut before the engine was started and the circuit energized. But thanks for playing. We all love snark.
For anyone concerned about starting the engine with the pump unenergized, Toyota RECOMMENDS doing just that when doing any work on the pressurized fuel system. See page SF-3, Par. 8a, in link below:
http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/02toyrm/02toypdf/02rmsour/2002/024runne/sf5vzfe/sfisy/prec.pdf
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