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Location:
Sydney
Registered:
February 2003
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: in event of a crash...
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Wed, 16 June 2004 06:11
 
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no idea, but i highly recommend the fuel pump relays from volvos. they detect if there are ignition pulses and trun off if there are none.
also some cars have crash switches, which permanently switch off the pump in the event of a high speed collision..
better to have a physical backup in case ECU's fry....
Cya, Stewart
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Location:
Brisbane
Registered:
May 2002
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Re: in event of a crash...
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Wed, 16 June 2004 06:19
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I've seen people trigger the fuel pump off the oil pressure sensor... as soon as the engine stops the fuel pump stops!
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Location:
Sydney
Registered:
February 2003
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Location:
Australia
Registered:
May 2004
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Location:
Adelaide, SA
Registered:
June 2004
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Re: in event of a crash...
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Wed, 16 June 2004 07:03
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What about just an in-cabin swith. Connected to the negative of the fuel pump. So it will always run as normal until the switch is flicked turning it off instantly. Perhaps a missle style switch, but turn it around so it is always on until you flick it? Yes, this will need to be activated manually, so if you are un-conscious it wont really help.
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Location:
Sydney
Registered:
February 2003
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Re: in event of a crash...
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Wed, 16 June 2004 07:10
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but im thinking this must be unnecessary,
surely microtech thought of this?
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Location:
Sydney
Registered:
February 2003
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Re: in event of a crash...
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Wed, 16 June 2004 07:16
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rang microtech:
apparently it just stops when the engine does.
they werent exactly sure on how 
but it does.
so i assume that it would have to be either:
the coil stops & it shuts off the fuel pump circuit
or
the map sensor sensing no pressure, shutting the circuit off.
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Location:
Sutherland Shire
Registered:
April 2003
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Re: in event of a crash...
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Wed, 16 June 2004 07:23
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Does your car work yet?
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Location:
Montrose, VIC
Registered:
May 2002
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Re: in event of a crash...
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Wed, 16 June 2004 09:38
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It's even easier, if your ECU can't manage it: go to a place that does LPG conversions, and buy a lock off controller. It's a little box that connects the IGN, GND, Coil - and the fuel pump relay, and when the engine stops, it has to less than 3 seconds later. You could even grab one from a wrecker  (They're about $20 new)
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Location:
Sydney
Registered:
February 2003
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Re: in event of a crash...
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Wed, 16 June 2004 10:23
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| 4a-c wrote on Wed, 16 June 2004 17:23 |
Does your car work yet?
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haha not yet.
it runs, but its not what id call driveable.
mrshin: that sounds like a good idea, even if the microtech "can" do it. just that piece of mind i suppose.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: in event of a crash...
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Wed, 16 June 2004 11:19
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| mrshin wrote on Wed, 16 June 2004 19:38 |
It's even easier, if your ECU can't manage it: go to a place that does LPG conversions, and buy a lock off controller. It's a little box that connects the IGN, GND, Coil - and the fuel pump relay, and when the engine stops, it has to less than 3 seconds later. You could even grab one from a wrecker (They're about $20 new)
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Mr Shin, thats exactly what the Volvo circuit does..
good to hear they are available new.. it is ALWAYS good to have a backup or even 2... oil pump switches are ok, but some can fail on.. you need a system that is gauranteed to dail off..
in the US i have heard they have "rollover/crash" switches.. usually in the boot, so if car stops suddenly, or is not the right way up, every shuts off..
microtech should do it, but you'd hope they knew why 
Megasquirt cuts off fuel if it doesn't get an ignition signal for 2 seconds.
Cya, Stewart
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I supported Toymods
Location:
Epping, Sydney
Registered:
May 2002
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Re: in event of a crash...
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Wed, 16 June 2004 13:46
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I know that with the microtech in my car, the fuel pump runs for 3-4 secs while key is on "on" position, then stops of the car isn't running. Dont know how unfortunately 
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Location:
Adelaide, SA
Registered:
June 2004
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Re: in event of a crash...
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Wed, 16 June 2004 22:48
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| draven wrote on Wed, 16 June 2004 23:16 |
I know that with the microtech in my car, the fuel pump runs for 3-4 secs while key is on "on" position, then stops of the car isn't running. Dont know how unfortunately
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All EFI cars do this regardless of what ECU they are running. I think it is to prime the lines.
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Location:
Canberra
Registered:
May 2002
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Re: in event of a crash...
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Wed, 16 June 2004 23:46
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I know my Haltech will only trigger the fuel pump after it detects an ignition pulse (and for a few seconds to prime the lines after you turn the key).
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Location:
Sydney
Registered:
February 2003
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Re: in event of a crash...
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Thu, 17 June 2004 07:00
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found out..
mines like draven's, i guess all microtechs are the same.
the pump runs for about 4-5 secs then turns itself off.
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: in event of a crash...
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Thu, 17 June 2004 10:47
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run it off a oil pressure switch! it is very very very important you guys all do this as if your knocked out or trapped in the car you are history. i have seen very expensive race cars go up in flames and the drive get badly burnt because it wasnt wired to a pump cut-off(imagine 2 bosch 600hp pumps at 65psi pumping avgas out!). if you get a pressure switch that switches at say 15psi it will save your life and also have the added bonus of saving you bottom end if the pressure drops as it cuts the fuel pumps, you will still have to change the bearings unless your really lucky or its low revs but bearings are alot cheaper than a rebuild.
mick
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Location:
Sydney, OZ
Registered:
May 2002
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Re: in event of a crash...
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Thu, 17 June 2004 12:25
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the D4s uses the ignition pulses ie see the flashing LED at the bottom.
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Location:
melbourne
Registered:
January 2003
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Re: in event of a crash...
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Thu, 17 June 2004 12:30
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| Sigmeister wrote on Thu, 17 June 2004 08:48 |
| draven wrote on Wed, 16 June 2004 23:16 |
I know that with the microtech in my car, the fuel pump runs for 3-4 secs while key is on "on" position, then stops of the car isn't running. Dont know how unfortunately
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All EFI cars do this regardless of what ECU they are running. I think it is to prime the lines.
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This is not true for all cars 
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Location:
Montrose, VIC
Registered:
May 2002
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Re: in event of a crash...
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Thu, 17 June 2004 14:53
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Plus many cars use rollover/hard impact switches on either the fuel pump, or the whole electrical system, that cut the power if something gets hit hard, or lands lid down
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Location:
Melbourne
Registered:
October 2003
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Re: in event of a crash...
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Thu, 17 June 2004 15:09
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Oil pressure switch is a good idea, the only problem with it is that it is switches negatively. In the very unlikely but still possible situation that the wire is squashed in between a panel, or somehow touches any metal part of the car the circuit can remain on.
Most EFI computers use the crank angle sensor, or ignition pulse
depending on what type it is. The wolf 3d computers when first
switched on (ignition) prime the fuel system by turning on the pump relay from anywhere from 1 to 255 seconds (adjustable) then
turns off. If any input trigger signal is detected, the pump is immedetly turned on again, and will remain on while input trigger pulses are detected.
Also holden style delco (1227808) also works on the same principal, and i would almost be my life that the microtech does the same as well.
As mentioned the LPG solonoid cutoff switches are the easiest to add in if your not running a computer and want a good auto cutout feature. Good for carby elec fuel pumps that would noramlly be pumping against a closed needle/seat vavle, getting
hot and heating up fuel.)
Man there are a lot of fuel blowing up stories out there
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Location:
On your mum!
Registered:
May 2002
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Re: in event of a crash...
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Fri, 18 June 2004 08:37
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Microtech do switch off by way of sensing whether or not the engine is running (ign input I believe) if there is no igntion signal, then it stops the fuel pump in a couple of seconds.
Try it with the engine running, stall the engine (easy if is manual) and you will see that the pump is disarmed in about 2 secs, this is the same as Wolf and the same as Nissan.
Factory Toyotas use (older ones anyway) a flip/flop relay that uses 1st signal from the crank wire and the 2nd from the airflow meter.
Oil pressure switch will be of little value when you are trying to start your car - at least until oil pressure is sufficient.
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Location:
Melbourne
Registered:
May 2002
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Re: in event of a crash...
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Fri, 18 June 2004 09:05
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Well i know that my pumps use a signal from the ignition coil, no spark no pumps. Dont know if this would be relevent in the event of a accident, but i dont plan to have one anyway so there would be no need to worry bout that
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