HELP - how to wire up a fuel pump

[mrshin]

If you want an easy way to make your pump run when the engine is turning only, with 2 seconds priming, and you don't have an ECU with FC pin, then just use a 'fuel lock control' from any car with LPG. Buying a new one will cost you no more than $30, a pre loved one much less, and they're dead simple to wire up.

[o_man_ra23]

yeah, but unless you have EFI, you dont need to pre-prime. And if you do have EFI, then you will have an output to use somewhere.

Cheers, Owen

[crowncustom]

Brett, that is required for EFI pumps to prime the lines so theres enough pressure, in a carby car this is not required as your floats take up the slack.

Timbo's wiring setup from an engineering point of view seems quite good. Failsafes are in place, current load is removed from unneccesary points, etc. I would say it would work perfectly.

Tapping into the ignition can be done by using a piece of a screw down terminal strip (about a dollar from dick sniffs). Cut a wire which runs from the ignition, and have one end in the strip on its own, and the other end paired with the wire for your fuel system. Also you can use a second point of strip to do the start wire in the same fashion. This is how ive been doing wiring mods in cars for years, and never once have had a faulty join. Make sure you screw down onto STRIPPED BARE WIRE, and not the plastic insulation.

Cheers, Owen

Yep very correct Owen.But even before EFI was totally on the seen this is how us old school mechanics used to wire up after market elec fuel pumps on carby cars.But yes Timbo's idea is spot on bit more complex but hey these days you have to be for safety.And your idea is spot on also in which is much the same idea as the way i've also been doing it.Problem with me I'm an old school mechanic coming to terms with EFI
Cheers Brett.

[o_man_ra23]

Yeah, clakka pumps work in the same way as the OEM mechanical pump, in that they only need fill the float bowl, the carby will take care of the rest. In this respect, pre priming is just extra draw on the electrical system. In all seriousness, you probably dont even need to run the pump on startup, as again, the float should take care of this. Problem there is if you flood it though, you can quickly exhaust the float's supply, so in this instance, pumping while cranking would be required.

Cheers, Owen

[mrshin]

I don't really see how letting the pump run for 2 seconds when you turn on the key is really such a serious issue though.

[Mos]

87 - normally open*. Connect this to your start wire.
87a - normally closed*. Connect this to your ignition wire.

explained graphically...

The 87 and 87a connections are interchanged on the first relay of the diagram. Connect it as per instructions and not the diagram (until timbo fixes the pic )

Mos.

[Mos]

My biggest querie is how can I hook up the ignition bit without tapping into the back of the fuse panel with one of those stupid clips? They arent good wiring practise in my eyes, just cause more problems.

One good way to tap into existing wires is to strip a portion of the insulation of the existing wire, wrap the additional wire around the conductors of the existing wire, and solder the two together. If done properly it gives the best possible electrical connection (not trying to stir a joint discussion).

If you're not confident soldering, get someone to show you how to do it and what a good solder joint looks like (nothing worse than seeing a blob of solder stuck to the side of the wire and someone telling you it's soldered!), or use o_man_ra23's method which is easier and in some ways better.

Those cheap blue IDC (insulation displacement connectors) clips are just ridiculous for anything that carries any significant current. "Proper" IDC style connectors cut (slightly) into the conductors themselves and provide a good connection but the common automotive ones are just garbage.

HTH.
Mos.

[oldcorollas]

and if you don7t have a soldering iron... a "jet lighter" is a fairly good substitute.... just don't set the rest of the car on fire

my fav is a little "revolver" styled lighter.. keep fingers away from dropping solder

[Mos]

and if you don7t have a soldering iron... a "jet lighter" is a fairly good substitute.... just don't set the rest of the car on fire

my fav is a little "revolver" styled lighter.. keep fingers away from dropping solder

The housing on those lighters has been known to melt, so be careful if the wires are thick One can only solder a few 8G cables with it before one needs to replace it. On the upside you can get them a lot of servos [at any ungodly hour ]

Mos.

[o_man_ra23]

One of the Techhies back in uni days warned me against soldering in any application that has lots of vibration... Reasoning being that the solder actually work hardens, and can form itself a dry joint (for anyone who doesnt know, a dry joint is where there is solder covering the join, but its not bonded itself to the material being joined. It looks somewhat like a good connection, but will have an intermittent fault which is almost impossible to find.) For this reason, combined with the vibrations normally associated with street driving, soldering is a non-preferred method. This is why I always use connectors. I will certainly agree that the regular auto connectors are crap as, but a proper crimper will improve their bond, and cause them to dig into the conductor. Still not as good as a screw connector tho.

Cheers, Owen

[sillycar chick]

I think I will go with Oman's screw style connector idea, the common automotive ones arent reliable. I know the type you are talking about, just didnt think of it myself
Not too keen on actually "cutting" the wire to connect it all up, but since the whole car has had bodgy wiring since I had it, I will do it anyways. As long as I can get a good contact and not get more intermittent/shorting/bad connection problems I have been having since I got the car.

[sillycar chick]

Next Question:
The diagram I have drawn up shows an inline fuse between the battery and the relay. THis is the only way I know how to do it. But, I already have two wires with fuses hooked up to my battery terminal. One is for for my headlights (I dont know why they did it like this but I dont know how to fix it/have been lazy) and one for my amp. If i hook up the fuel pump that will be three. Soon I want to hook up a thermo fan... then there were four.... and the list goes on....

Is there a way I can set up my own fuse panel hidden in the engine bay so that I can have one wire to the battery terminal and run all the relays from this panel? it seems like the obvious solution but I dont know how to go about it....

[o_man_ra23]

Fused terminal blocks can be purchased in many forms, ranging from ones which incorporate the battery clamp to ones which are standalone, and they also range highly in their power ratings. Research Jaycar and Dick sniff's range, and you will see quite a few different ways. You can also buy the fuse blocks from autobarn, supercrap etc.

Cheers, Owen

[sillycar chick]

I have seen them at supacrap... How could I wire one up so that I only have one wire going to battery but multipe fuses with power going to them?

[o_man_ra23]

They should have one side that you can solidly join the terminals, and the have separate terminals on the other side of the fuses. Dont forget to still put a big arse fuse on the cable that goes to the fuse block, as this will protect the wire going from the battery to the fuse block. Find out the MAX amount of current you will ever be able to draw from the cable (dont just add up the fuse values you use) and get the next biggest fuse, and plonk that inline.

Cheers, Owen

Edit: put the fuse as close to the battery as inhumanly possible.