Beaver Posted July 3, 2013 Share Posted July 3, 2013 Have had a browse of the interwebs but there seem to be too many retards in this world. Im going to put an electric pump and just wanted to bounce some ideas around for the wiring and see what others have done. I will wire it up with a relay and have it switched from the ignition so the key has to be on. I will also put a on off switch inline with this so both need to be on (both security but also so the car can be on but have the pump off). Some recommended to have an automatic cutoff switch so that in the event of a crash or whatever the pump will stop. It appears the most common is an oil pressure switch? I think I also recall some people using a rollover switch of sorts so it the car is upside down/on its side the pump will stop. Is this needed? Can anyone recommend something to use? Could I possibly tap into the existing oil pressure switch to trigger this? Cheers Quote Link to comment Share on other sites More sharing options...
JoKer Posted July 3, 2013 Share Posted July 3, 2013 Oil pressure not so hot Idea (My old avenger oil light used to flicker the light at idle) ninja edit : you don't want to be running lean on the banks of a 'drome @ 22psi either should you hit surge/melt a piston etc. Reed switch or a mercury one is good for "excessive" angle/roll-over something that isn't activated by going over rail tracks etc be ideal Neal (like a motion switch on an alarm if someone tries to nick your rims etc) the above is pure speculation and not from real world experience other than the mentioned flickering oil "Idiot" light Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 Don't bother with a safety switch. put the aux on/off switch between the sense wires of the relay, done. 1 Quote Link to comment Share on other sites More sharing options...
Beaver Posted July 3, 2013 Author Share Posted July 3, 2013 Sweet, I was just wanting someone else to agree that safety switch was a bit silly...haha. Another question, I think ive got it right, but the ignition switch will also be in the "sense" circuit of the relay yeh? And the main/high power circuit will be straight form the battery (with a fuse inline), and then to earth. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted July 3, 2013 Share Posted July 3, 2013 Run the ignition switch to the sense side and the kill switch to the earth side. Well that's what I would do. 2 Quote Link to comment Share on other sites More sharing options...
mfordy Posted July 3, 2013 Share Posted July 3, 2013 I've interocked the fuel pump via a relay driven from the oil pressure switch. Don't like the idea that if I'm upside down somewhere and the fuel pump is still pushing fuel into the carbs. You will also need to wire in a defeat circuit for startup. Quote Link to comment Share on other sites More sharing options...
Beaver Posted July 3, 2013 Author Share Posted July 3, 2013 You will also need to wire in a defeat circuit for startup. expand please? Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 TBH if you are in a ditch somewhere, you have bigger problems if you cant turn the car off. This is standard wiring for a relay. What KK and I are talking about is just putting the kill switch on either side of the 85 86 circuit, but it makes no difference. I would put in close to where you got the ign feed from because it would make packaging slightly easier, assuming you are going to take it from the key area, and then just put the earth to the mounting bolt for the relay, but it would all work. And yea constant +12 v to 30 and 87 to the +ve side of the fuel pump. Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 expand please? When the car isn't on you don't have any oil pressure, so you fuel pump won't go, so you can't start it. To counter this you have to wire in a separate circuit that when the car isn't on you can over ride it to turn the fuel pump on so you can start it. Basically a huge fuck around for no good reason. Quote Link to comment Share on other sites More sharing options...
mfordy Posted July 3, 2013 Share Posted July 3, 2013 Basically a huge fuck around for no good reason. Happened to a mate of mine. Was unconscious after a crash, damaged fuel lines and fuel spewing everywhere. Seems like a pretty good reason to me. Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 Meh, he has all the information now, he can decide. I wouldn't do it, as many manufactures in past have not. As you can tell by all the people who burned to death when they crashed their car, it is a VERY important safety feature.... Quote Link to comment Share on other sites More sharing options...
Seedy Al Posted July 3, 2013 Share Posted July 3, 2013 heh, rookie. Just because you wouldnt do it, doesnt mean other people shouldnt, ot shouldnt not choose to do it. I was interested to hear what sort of circuitry you used to by pass the oil pressure switch while on start up? I have a fairly good idea, but but its always nice for other people who dont to have something to read Quote Link to comment Share on other sites More sharing options...
be4ver Posted July 3, 2013 Share Posted July 3, 2013 You would need two relays to do it but the way I imagine it it would only work if your starter had enough balls to build the oil pressure to the point of the switch opening up. otherwise have a button that you have to hold to power the fuel pump while starting it Quote Link to comment Share on other sites More sharing options...
be4ver Posted July 3, 2013 Share Posted July 3, 2013 But... the carb should hold enough fuel in it to start the car anyway with out having to pump first? 1 Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 Wow you guys are totally overthinking something which isn't even a problem. Hot rodders solved this 50 years ago and nothing has changed since... Quote Link to comment Share on other sites More sharing options...
AllTorque Posted July 3, 2013 Share Posted July 3, 2013 Are you planning on getting a cert for anything in the future? I have a feeling the pump must turn off when the engine stops to pass cert. It may pay to check with Cletus Quote Link to comment Share on other sites More sharing options...
Rookie Posted July 3, 2013 Share Posted July 3, 2013 It will. Quote Link to comment Share on other sites More sharing options...
Beaver Posted July 3, 2013 Author Share Posted July 3, 2013 Yeh eventually. Good point. Will look into wiring a relay off the oil pressure switch Quote Link to comment Share on other sites More sharing options...
be4ver Posted July 3, 2013 Share Posted July 3, 2013 This crude scribble is how I would do it, it's probably much more complicated than it needs to be but that's just how I roll. Push button will need to be normally closed Quote Link to comment Share on other sites More sharing options...
Beaver Posted July 3, 2013 Author Share Posted July 3, 2013 pretty sure that push button will bugger everything up. When its not pushed in the the oil switch is ignored so defeats the ppurpose/wont activiate the relay? Quote Link to comment Share on other sites More sharing options...
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