Fitting a Huco electric pump

[markcro]

I received a Huco electric pump for my GT6 yesterday and was wondering where is the best place to fit it? Also do people just wire it directly to the ignition switch or do they fit a relay? Also do they fit a safety switch? (I know that this last one is recommended but do many do it?)

Thanks.

[don cook1]

I'm in the process of trying to find a white wire under the dashboard to connect up to. Safety switch makes sense. Mine is on the bulkhead, someone else has fitted it in the space where the old mechanical pump was but see where you have the room and how the fuel lines will run.

[piman]

Hello Markcro,

there are two types of pumps one to be fitted near the tank, the other to be fitted in the engine compartment, you need to see which you have?

Don, you know the white wires are unfused? An easy access is at the fuse block for white or green (fused)

Alec

[don cook1]

Had a look at the fuse box but can't see how to remove/add wires, there doesn't seem to be any screw or plugs to loosen. I'll have an in-line fuse in the power supply to the Huco.

[markcro]

The pump that I bought is the suction type so has to be fitted in the engine bay. When fitting to the bulk head, how did you do it? Just used self-tapping screws?
I’ll have to buy an inline fuse so. Any idea of the rating?

On a separate note, what do you use when you need to connect additional wires to the battery terminals? Are there large spade connectors or what is the norm? At the moment I have wire clamped in under the terminal for the electric fan etc. and it looks awful.

[piman]

Hello Don,

is it original or after market? Normally I would expect to see standard lucar female connectors on the original wiring? If there are no spare blades on the fusebox, cut one of the wires as close to the terminal as possible and connect your new cable to the original and crimp a single terminal over both.

Alec

[piman]

Hello Markcro,

you can get large ring terminals, probably even Halfords will stock them. But do ensure you get the inline fuse holder fitted, I don't know what current the pump pulls but I would expect a 5A fuse to be suitable?

Alec

[don cook1]

I used two thick rubber washers between the bulkhead and Huco clamp, secured with large, short self tappers. Some people don't mount on rubber. I got a handwritten note from the Huco supplier stating err...I think 3 or 5 amp fuse but can't find the note, so piman is probably correct.

I'm giving up on the fuse box and will look for a green wire, there's one at the wiper motor so I'll try that. I'm after neatness and don't want dangly bits all over the place.

Markcro - you need to take your fuel pump power supply from a source that is switched off when the ignition is off, that will stop your pump from running. Good place for your engine radiator fan wire is from the white coil wire. Unless you want it running while its switched off, in which case I assume it has a reliable thermostatic switch.

[markcro]

Good tip on the white coil wire Don - cheers!  Why don't some people mount on rubber?

[Dannyb]

You should fit a safety switch in case of accident. I have an oil pressure switch fitted to the side of the block so if engine stops in an accident the switch cuts off the pump.
http://www.ebay.co.uk/itm/Long.....;hash=item4865e4c47f

[markcro]

That is an interesting idea with the oil pressure switch. Where would be the best place to pick up a t-piece so to keep the oil pressure sender in place also? (sorry for being lazy!)

[RobPearce]

The oil switch solution isn't as simple as the inertia switch. The latter will always conduct until you crash, at which point it will be open until manually reset. That's what you want, so you just wire it in series. The former is open when there's no oil pressure, but that's always the case when the engine's not running yet, so you won't get any fuel to the carbs on a cold start. To get round this you need, in parallel with the oil switch, a priming system. This could be a time switch activated by ignition on, or it could be a relay driven by the starter solenoid (if you have a late solenoid with an early, non-ballast, ignition system then you can use the ballast bypass terminal on the solenoid).

[BiTurbo228]

Quoted from RobPearce

The oil switch solution isn't as simple as the inertia switch. The latter will always conduct until you crash, at which point it will be open until manually reset. That's what you want, so you just wire it in series. The former is open when there's no oil pressure, but that's always the case when the engine's not running yet, so you won't get any fuel to the carbs on a cold start. To get round this you need, in parallel with the oil switch, a priming system. This could be a time switch activated by ignition on, or it could be a relay driven by the starter solenoid (if you have a late solenoid with an early, non-ballast, ignition system then you can use the ballast bypass terminal on the solenoid).

But on the positive side if you blow a core plug or something it'll cut fuel so the engine will stop. Probably not quick enough to avoid damage on a carbed car, but perhaps on an injected one...

[RobPearce]

Quoted from BiTurbo228

But on the positive side if you blow a core plug or something it'll cut fuel so the engine will stop. Probably not quick enough to avoid damage on a carbed car, but perhaps on an injected one...

Not sure how an oil pressure switch would detect the loss of a core plug, which are on the coolant system, but if a gasket fails or the filter works loose or whatever... I suspect it would probably be too late by then.

These oil pressure switches were used on some cars (Austin Montego, for one) but only carburettor ones AFAIK. The inertia switch works better as a safety device, especially on injected cars, because it will cut the fuel after a major shunt that fractures a pressurised fuel line but doesn't kill the engine. Having seen how far a Spitfire can be driven on the fuel that manages to jump a half inch gap and hit the other pipe...

[sam93]

Here's where I've installed my Huco fuel pump. There's a thick piece of metal behind the plate where the mech fuel pump would go, acting as a proper blank. Like you rightly said, i didn't bother fitting a cut out switch as I don't intend on driving so hard that there's a possibility of rolling it. I've also attached a picture of the replacement fusebox that I've installed, the wiring isn't connected as I've just finished a harness rebuild & have finished clipping it back into place.

Hope it helps,
Sam.

[drofgum]

Sam,
A safety switch isn't only for rollover situations. It shuts the pump off in circumstances when it might be pumping fuel through a broken line and increasing the fire hazard. Only fully automatic fuel cut-off should be considered acceptable.
                                                                                            Be safe,
                                                                                            Paul

[markcro]

Quoted from sam93

Here's where I've installed my Huco fuel pump. There's a thick piece of metal behind the plate where the mech fuel pump would go, acting as a proper blank. Like you rightly said, i didn't bother fitting a cut out switch as I don't intend on driving so hard that there's a possibility of rolling it. I've also attached a picture of the replacement fusebox that I've installed, the wiring isn't connected as I've just finished a harness rebuild & have finished clipping it back into place.

Hope it helps,
Sam.

Ah I like that! You mounted it on the block where the original pump was?
To start with I won't have a safety switch, I'll just have it wired to the ignition. In the case of a smack I'll turn off the ignition. Nice job on the fuse box as well.