Fuel Pump question
Turbo Mini Forums

Hi Lads,

All good just a quick question regarding the fuel pump. I have the wirring diagram. Just one thought though. Is the Ign Feed ok to run the pump or will that add to much current? How ahve you boys done it?
Just used the starter feed and ignition feed to run the pump off there exsiting fuses and cable?

Most people run a relay off the ign + starter feed i think, as the pump does draw a fare few amps.

To be safe, I would fit one.

Edited by Carl S on 8th Jul, 2008.

plus a collision switch of a mondeo to just to be on the safe side.

you can find them in the passenger footwell

always looking for them bigger bunches of bannanas

The diagram i have uses those feeds to run the pump.
Has any one got a diagram then of one that you use your own feed but still has the low oil pressure facility?

Hi,
The ignition feed and the starter feed are the only ones you can use for that relay system. I don't quite follow what you're saying here... ^
Cheers,
Gavin :)

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So what your saying is then, the two feeds are running the pump? My concern was that the pump does pull a fair current and wondered if these are man enough to cope with the extra load?

i used the white ign feed from the ing wiring to trigger the relay and took main feed of unfused side of fuse box but with a inline fuse in, then take feed from relay to pump.

along with the inline fuse i ran it through the fuel cut off swith from a mondeo

always looking for them bigger bunches of bannanas

Hi,
This is the way I would do it....



Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

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Most efi pumps start around 7amps, with the biggies drawing as much as 13 amps at full load ( which isnt that often, unless running a lot of pressure. )

Id guess that in a low pressure carb situation, current draw would be much less.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Total current draw for my car at tickover is 4 amps. This may rise as fuel pressure increases.

I use an output on the MS to feed a relay. The pump only runs when the MS sees crank rotation.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Is there a way of testing that setup works, should the pump stop when you earth the oil pressure feed?

personaly i would use the motion switch method as an engine can still be running after a crunch so the oil pressure switch method wouldnt stop the pump. but with the motion switch used at least after a shunt the pump would be switched off, so reducing the risk of a pressure feed fuel supply being pumped into the engine bay

always looking for them bigger bunches of bannanas

Sorry to sound like a novice here but i'd like to get my head around this! That relay connection diagram wont work that is shown above.
How does the inertia switch work? Any ideas of a cost?
Any other ways that you boys have done it?

Hi,
Sorry, edited diagram as my brain had broken down :(
As stated above and in the diagram, use an inertia switch.
Better than using the oil pressure switch would be to use a tachometric relay which senses the pulses from the negative side of the ignition coil.
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

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My Mini build diary

just fit the intia switch in line with main feed to the relay from the fuse box

always looking for them bigger bunches of bannanas

Yep I agree that cahange to the diagram does work. however while your cranking the engine before it fires you are feeding the pup via the red and white thin crank feed. The way around this is to fit another relay before this one and use the crabk feed to operate the coil of the new relay and loop the run the feed through this new one.

So this inetia switch then, it cuts the fuel off if you have an accident? How does it no with out sensors?

Schrödinger's cat - so which one am I ???

So where can i get hold of one of these switches and how much are they? So is it a case of the feed in and then out to the pump, no control wirring? Apart fromt the other relays of course!