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Facet fuel pump question

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by Paul_S, Mar 17, 2018.

  1. Paul_S

    Paul_S
    Z Club Member

    I've no experience of fuel pumps so I'd like some advice please.

    My car has a Facet pump mounted by the fuel tank and when I powered it up today it didn't make a constant noise as I was expecting, but about 1 second of a very rapid tapping noise, then silence, then the noise again, repeat...

    It is pumping fuel but the fuel only flows when it makes the hammering noise and so is pulsing of the hose.

    I assume this isn't right? I would expect a constant noise and a constant flow of fuel.

    The pump hasn't been run for 10 years so is there something I can check / clean / replace or is it not worth the hassle and just buy a replacement?

    Thanks :)
     
  2. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    They normally pump quite loudly until the float chambers are full and then quieten but keep ticking.

    What sort of pump is it - take a picture for us.

    Some have a 'cleanable' fuel filter in the base and these can get blocked with fuel tank rust particles.
     
  3. Paul_S

    Paul_S
    Z Club Member

    Ah, so perhaps it's OK because I've just been letting it pump fuel into a bottle for the moment to clear the lines out.

    Here's a pic:

    [​IMG]
     
  4. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    No it should keep pumping loudly if you have an open pipe, not stop.

    The bottom of that pump will twist and reveal the filter but it can be very tight. I did mine in a vice.

    Your wiring looks dodgy. Is that green, red/white, red wire doing anything? Fuel tank sender wiring?

    The pump needs to be earthed from it's mounting bolts. The pumps should be mounted on rubber mountings to reduce noise - I can't tell from your pic about the rubber and I can't see the earth wire.
     
    Last edited: Mar 17, 2018
  5. Paul_S

    Paul_S
    Z Club Member

    Ah, I thought that might be the case (regarding the noise).

    I'll remove the pump and take a look at the filter, etc. When I disconnect the fuel line from the tank might I expect fuel to pour out? I've about 8 litres in the tank.

    You are right about the wiring, I haven't looked that part of it properly yet. It's also a good spot on the rubber mountings, I don't have any and I didn't realise that until I started looking into new pumps for sale.

    Thanks Rob :)
     
  6. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    Folks what is that pipe for that is routed across the car (and the yellow wire cable-tied to it)?
     
  7. toopy

    toopy
    Z Club Member

    I have a similar Facet pump, but mine is in the engine bay.

    As Rob says, it's noisy at first, for a couple of seconds or so, then once the back pressure comes up as the float bowls max out it quietens down, you can still hear it while the engine isn't running, but its drowned out once started!

    Is your fuel return clear?
     
  8. toopy

    toopy
    Z Club Member

    Also I would fit an inline filter with a clear case, before the pump, that way you can easily see how grubby its getting without the hassle of trying to remove the filter in the pump base, which as Rob also says can be trying to remove, especially when its still bolted to the car!

    With my pump i ran a seperate earth lead in addition to relying solely on the mounting bolts :)
     
  9. Paul_S

    Paul_S
    Z Club Member

    Thanks again for your advice folks :)

    There is no fuel return on mine. I might well run a new earth wire too because I want (need) to run a new live anyway.

    Good shout about the clear filter, thanks. There is one under the bonnet but it's a bit late then!
     
  10. Paul_S

    Paul_S
    Z Club Member

    Well, I took the pump off today (it did have rubber mountings and a proper ground connection after all). I tested it on the bench and it did the same. The whole thing looked clean and didn't appear to be seized but the piston was very scored:

    Fuel filter:

    [​IMG]

    Pump with filter removed:

    [​IMG]

    Pump inners removed (piston, spring, etc.)

    [​IMG]

    Scored piston:

    [​IMG]

    So I've decided to buy a new pump. I'll let you know how it goes
     
  11. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    That pump was indeed very clean! When I took mine apart I couldn't believe it could pass fuel!

    You may have not needed a new pump but you now have a spare - I had to replace one recently.
     
  12. toopy

    toopy
    Z Club Member

    Is that green wire in your photo not live with the ignition on? I would assume that is the OEM wiring for said fuel pump wether it was actually fitted at the factory or not.

    If it is, but you want to err on the side of caution regards the old wiring, you could just use it to energise a relay that then feeds the pump via some new wiring o_O
     
  13. Paul_S

    Paul_S
    Z Club Member

    I haven't actually ordered a replacement yet but this one doesn't seem to work as it should. I couldn't strip it down any further than you can see in the photos so I can't find the fault unfortunately.
     
  14. Paul_S

    Paul_S
    Z Club Member

    The wiring is 'interesting'! The green wire which goes to the red/white wire, which goes to the red wire is earth.

    The black wire from the pump joins the (reduced gauge) yellow wire you can see which then joins a black wire that just runs along the floor under the mat until it joins another wire which finally joins a different wire that goes to the ignition switch.

    Like I said, it needs some work! However, right now I just want to prove the engine runs and I will take it from there. I was thinking about fitting a relay because, whilst I don't know what current the pump draws, I would be surprised if the ignition switch was designed to take it.
     
  15. toopy

    toopy
    Z Club Member

    IIRC they are around 5amps, so not excessive, but even so, the less going through the ignition the better .
     
    Paul_S likes this.
  16. Paul_S

    Paul_S
    Z Club Member

    Yes, it's good practice. I also need to fit replays for my headlights so I am thinking of buying one of those boxes which house multiple relays to keep the new wiring all together.

    I forgot to post up this link which might be useful for anyone trying to identify which model Facet pump they have (basically read it off the numbers stamped on the feet) --> http://www.dummett.net/ime/website/ime/a2z/facet.html

    Here's a copy of it in case the link dies at some point:

     
  17. Paul_S

    Paul_S
    Z Club Member

    I just realised I didn't update this. The new pump works fine and is A LOT quieter than the old one :)
     
  18. yellowz

    yellowz
    Z Club Member

    What pump did you get?
     
  19. Paul_S

    Paul_S
    Z Club Member

    It was a like for like replacement. Another Facet 476087 Silver Top.

    I was working on the assumption that the previous owner got the right one. I hope that's not a mistake!
     
  20. toopy

    toopy
    Z Club Member

    You want pressure around 4-5 psi on carbs, so the above should be just fine EXTRA:)
     
    Paul_S likes this.

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