Hi Guys,
 
Whats the best way to wire up a fuel pump?
 
I am using a bike fuel pump for my bike carbs and I just have the power coming from the fuse box.
 
Should I take power from the starter motor (as battery is in boot) into a relay then onto the pump or will just a wire from powered ignition source be fine?
 
Cheers,
 
Matt 

Hi Matt,
I personally would use an ignition power source to trigger a relay. The main power(not the trigger) to the relay could be picked up of the fuse box or the starter it's up to u. Either way u need to ensure that there is a fuse in the main supply somewhere. If wired off the ignition u only power the pump when the ignition is in the run or start position.
 
Cheers
Craig

Matt,
If it were me I would take a fused power feed (10 amps) from your starter solenoid or battery to the power side of the relay( terninal 87 on a relay normally),and from the switched side of the power relay, terminal 30 to your fuel pump active, ground your fuel pump to the body work, that is the power circuit sorted. Now for the control circuit, take a ignition switched active to a ignition pulse controlled relay (used in LPG gas systems as a LPG solenoide safety cut off) then the output of this to termial 85 on your fuel pump relay. Ground terminal 86 of your relay the the body work. You will need a power feed to your LPG ignition relay, just use the fused power feed from your fuel relay and also a ground to the body of the ignition relay. Plus an ignition pulse input from your coil, normally the -ve side.
 The reason for doing this is, if you have an accident without the fuel cut off provided by the LPG relay, the pump will keep pumping and if your fuel lines are cut, this is not a good thing for you or anyone trying to help you. When you go to start the car, turn your ignition key to on and your LPG relay will prime the fuel pump for up to 5 seconds or so if no pulse input is detected it will turn the pump relay off again. When you turn the key to start the relay will sence the pulse from the igniton and close the relay contact until you turn the car off, so if for any reason, say your engine stalls due to an accident or what ever your fuel pump will be turned off, a very good safety thing to have and at $35 or so even more so.
 
Scott

Thanks Craig & Scott for your replies.  Will grab a relay next time I'm out.
 
Scott, I like that idea.  Where can you get the LPG ignition dealie from?
 
Cheers,
 
Matt
 
 

Matt
Any place that does LPG conversions, or an auto sparky, also check out ya local auto salvage might pick 1 up for 5 bucks
Scott
 

Should have asked me to show the setup on mine today. I use an lpg relay for the twin fuel pumps.

D'Oh!  That's cool.  I am pretty sure I have it sussed.
 
Thanks again for the brake pipe.
 
Cheers
 
Matt

Another option
If you wire the relay coil trigger to the small ignition wire at the alternator, this will switch the pump on when the alternator starts to charge (engine running) and  off if the engine stops. fit a primer push button on the dash to the same wire with an Ign+ to the other side of the switch you wont need an LPG timer.

Good idea!
 
Cheers,
 
Matt