Fuel Pump Direct Feed Rewire.

[Cubes]

Cubes - how did you attach the 8GA to the std fuel pump plugs?

<{POST_SNAPBACK}>

I run an external pump.

I then spliced the wire from the plug in to the 8ga feed going to the external pump.

[Craved]

I run an external pump.

I then spliced the wire from the plug in to the 8ga feed going to the external pump.

<{POST_SNAPBACK}>

ok.. so you are still running the std wiring to the std pump .. but feeding the power from the battery feed.. kk

i was gonna run 8GA wire direct to the plug.. bypassing the standard wiring all together ..

[Craved]

just had a thought .... isn't the std fuel pump fuse only 15amp ..

cubes .. your running a 30amp fuse on the pump now ... you know if that would cause any issues to the pump?

[benl1981]

So for 200rwkw I shouldn't bother with this mod?

If I did do it does it not matter that you have say 20mm of the thinner wire before you splice it?

Thanks

P.s. at the moment Im at 85% duty cycle on the base PFC map. I guess it will be reduceed a little after the tune. but If the fuel pump cant maintain the appropriate fuel pressure at the rail you will get less flow thought the injectors for a given duty cycle.

Edited November 23, 2005 by benl1981

[Cubes]

If I did do it does it not matter that you have say 20mm of the thinner wire before you splice it?

<{POST_SNAPBACK}>

Unsure.. Would probably be ok.

One benifit of running the stock pump as a lift pump and the big pump as the external.

[benl1981]

Don't think I will bother with this if it is believed 200rwkw will be ok on stock pump and wiring...

[Cubes]

Suck and see as they say.....

I did it because I was bored and trying to avoid my end of year uni assignments.

Its an easy mod.

Just in case I wasn't clear, the external bosch pump has 8ga running directly to and from it.

Edited November 23, 2005 by Cubes

[benl1981]

Cool thanks. I'll check it out...Cubes do you know what the other 2 wires are for?

[Cubes]

No idea.. Mines an R32.

It has 4 wires.

Throw a multimeter on to it, disconnect them etc to see what happens.

Edited November 23, 2005 by Cubes

[Craved]

ben

the 3 other wires is for your fuel level sensor ..

<{POST_SNAPBACK}>

then +ve and -ve on the separate plug.

-- yeah im using my std pump as a lift pump to the surge tank too ..

will see what i can organise with pics etc .. might as well make a tutorial out of it for the DIY section.

[Craved]

i've got no trigger power coming to the fuel pump relay in the boot...

so when i turn the key there is no change to any point on the relay ... its either a problem with the ECCS (dunno what it does) relay .. or i'll have to bypass the whole system and have the pumps on constant power.

what a hassle lol.. at least i've already bought everything to do it with.

[Cubes]

Definitely a bugger.

Grab a copy of the r33's ecu pin out. Check that power is coming from the fuel pump pin.

[Craved]

Definitely a bugger.

Grab a copy of the r33's ecu pin out. Check that power is coming from the fuel pump pin.

<{POST_SNAPBACK}>

yeah i have the manual. ... but i only remembered the ECCS relay exists after i left for work tonight .. it will have to wait til tomorrow arvo when i get up .... soooo annoying to have an idea on whats causing it and be able to go check now LOL

[Craved]

after all my efforts, one of the relays i bought for the pumps were faulty... left me stuck on the side of the road for ages....

/end rant

time to go get a replacement.. and try again

[Cubes]

Bugger...

[HKS-R33]

Hey guys, sorry to bring up an old thread but when using a single intank bosch pump. Do you use a 60amp horn relay or a 30amp?

Thanks, Mike.

Edited June 4, 2006 by HKS-R33

[Cubes]

I ran a 60amp horn relay as I had suitable 8ga I believe it was connectors for it.

[tacker]

HKS,

i did this mod some time ago. The 30 or 60 amp rating is for the contacts in the relay and 30 amps is more than enough for the single intank pump.

I also ran the negative from the battery to the boot along with the positive in a 6 mm2 cable so there would be no voltage drop under load.

I also see some comments about controling you relay from an ignition source which is what i did.

And as an after though running the pump at 13.8 volts is much better than at 11volts, as the lower your voltage the higher your current ( amps ) the sooner you burn out the pump.

[r33_racer]

Simple electronics, volts go down, amps go up, when amps go up, motors run hotter, which equals burnt out motor sooner.

Outta curiosity is the 8ga cable that you used Cubes some 8mm thick auto cable or something similiar?

[Cubes]

I also see some comments about controling you relay from an ignition source which is what i did.

As I mentioned in my origional post I used the fuel pumps origional feed as the trigger, works much better and safer than simply using your ignition source.

If the car stalls the fuel pump won't keep pumping, if you were in an accident having the pump continue to pump could lead to a very nasty fire.

This is what I used...

8GA Cable 8GA has a total diamater of ~6.5mm, the 4ga was simply too thick and overkill, + crimp connectors were not available for easy relay and fuel pump connection.

Big arsed fuse holder I have several spare fuses just in case one day.... Its mounted up near the hicas controller under the rear parcel shelf.