all electric fuel pumps

rodeo bob · rice boy Joined: 04 Aug 2003 Posts: 24

having fuel pump trouble? want to go to electric fuel pump? want to change to a bigger non genuine type alternator on your elec pumped car?? ive just had to go from mechanical to elec fuel pump and i needed a safety system so when the engine was off so was the fuel pump. i made a whole new system for less than say $50(+pump) that will be just as safe as the factory set up. i went to the auto elec and told him what i planned to do and he said it was the only way coz the purpose made retro fit thing cost mega bucks ($180). get a gas solenoid cut out switch from your local gas joint (got one last week it cost $27). get a heavy duty fuse holder(blade type from dick smith about $ Cool

get a relay(if your fitting a 12v), wire and terminals and borrow a soldering iron if u aint got one. use some heat shrink if you want it looking all flash. wire it all in and you will have a safe 12v to your pump.
how to?
the gas cut out needs four wires hooked up, 1(gas switch) 12v+ ignition feed (preferably not the coil), 2 -pulse from the coil, 3 (gas solenoid) + out for the relay/fuel pump. 4 earth (depending on the switch it could be a moulded in metal bracket) wire up relay and the fuse (pump side of the relay) plumb it down the old wire to the tank or run a new one if youve fitted a bigger pump.
these types of switchs usualy have a short prime time when you turn the key on each time before the engine starts(2 sec). ive had no trouble with running the fuel bowl empty trying to start my old beast yet (4ZB1 in a rodeo) but if i did the only thing to do would be wire in a prime switch. when i first got the motor in i just used a bit of wire direct from battery to the fuel pump to fill the fuel bowl.
you could get the cut out switch and the fuel pump from the wreckers to save on the dosh. any dual fuel vehicle will have the cut out and the pump ive got is an in line one off the shuttle that the motor came out of. any non efi factory inline pump should do the trick, but take care with the voltage and if its meant to be direct earthed or not. check the donor car and see if you need a fuel return and use a multi meter and check the voltage. if there is no engine in the car or the engine wont go get a battery [disconnect start wire to the starter motor] and get some one to turn the key to the start position and hold it(ive drained a few tanks this way). the shuttle didnt have a return and the pump is of a fairly low pressure. the old mechanical pump had a fuel return so with the pump removed i just blocked off the line to the tank. i mounted my pump above the rhs engine mount under the inlet manifold where the mechanical one was on the 2.3, i left it on the plate with the rubber isolators. its had no trouble sucking the fuel through from the tank. the shuttle would have had a cut out system for its pump and id say it was alternator related the same as the gemini but as with one model to the next its not always apples for apples. if your replacing your in tank job with an in line off another car take care not to over power it or it may not last long. things like pumps and ignitions are quite often resisted back to 8 or 9v for reasons unknown to anyone surely the extra cost per unit to make it 12v would be less than the cost of all those millions of resistors.
take care and think twice, pay once.

Blue TG · tinkerer Joined: 10 Feb 2003 Posts: 183

i got an easier way.... buy a fuel pump, whatever suits your needs, and then run the relay for it from the active of your airbox fan

have you ever noticed that doesnt work til the alt. is apinning??

that gas solenoid stuff seem like a big waste of time to me and as long as you dont solder like a two year old, you wont have any problems, i havent

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Whats an airbox fan??

rodeo bob · rice boy Joined: 04 Aug 2003 Posts: 24

its alright if youve got a fan but you tell me how you would do it from scratch on an alternator with an in built regulator????? its also running its own seperate circut so if your fan thingy shits you wont spend hours stuck coz your fuel pump cut out.

Blue TG · tinkerer Joined: 10 Feb 2003 Posts: 183

you run from the active wire, before the fan, so that if your fan thingy shits, it dont do shit all to the pump.
an airbox fan is your heater, front demister etc

rodeo bob · rice boy Joined: 04 Aug 2003 Posts: 24

yeah that would work if your fan shits and earths because of the extra load on the circut. get it right mate i never said you couldnt use the fan i posted to help out someone with the same trouble as me. if your heater fan cuts out with the engine its got the alternator not spinning set up in it. therefore in theory good use that circut. but if youve got an inbuilt regulator theres pwr at the alternator all the time the fan goes if the key is on all the time. i never said this is the only way. its the way i did it.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

My Fan comes on with ignition. It doesn't wait for the fuel pump relay before it gets power. The fuel pump relay is the only thing that switches on my can after the alternator starts spinning. Its all standard, TD.

Ben

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

another way to hook up your fuel pump is off the aircon wire you may want a switch in there as it is always live.

Frederick Stienheld · petrol head Joined: 05 Sep 2002 Posts: 2719

The *real* aircon power wire is only active when
1) The car is on &
2) The fan is on

pig75 · tinkerer Joined: 11 Jan 2003 Posts: 72

With a in built reg alt all you do is hook up a SPDT relay too the waring light and ignition wire that way when the alt light is on the pump wont work then when it starts charging the pump will run. It’s easy

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

not in mine is live as soon as the u turn on the battery isolation switch.

tx1975 · tinkerer Joined: 21 May 2002 Posts: 321

if i recal , the aircon fuse at your fuse box is always permanent 12v, so u can use it for accesories if u dont have aircon.