No noise from the fuel pump | FerrariChat

No noise from the fuel pump

Discussion in '308/328' started by Transient, Apr 27, 2017.

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  1. Transient

    Transient Karting

    Sep 6, 2007
    110
    Sydney Australia
    Full Name:
    transient
    Hi guys,
    A few weekends ago the fuel pump stopped making the wizzing noise when i turned the ignition on. BUT, the car starts, idles, accelerates and drives as normal. All pressures and temps are completely normal as well.
    Should I be concerned if I can't HEAR the fuel pump? It's obviously working, right?

    Thanks in advance...
     
  2. ME308

    ME308 Formula 3

    Nov 5, 2003
    1,542
    Munich, Germany
    Full Name:
    Michael
    when turning on the ignition (engine not running) you will NOT hear the fuel pump -
    if everything works as it should ;)

    the fuel pump should only be audible if you unplug the blue/green safety switch on the fuel distributor and turn your ignition key to on


    well, seems now everything works as it should ... but clean that switch ;)

    .
     
  3. Albert-LP

    Albert-LP F1 Veteran
    Owner Rossa Subscribed

    Sep 1, 2010
    7,779
    around Modena, Italy
    Full Name:
    Alberto Mantovani
    you every day learn something, here: where is that switch? and, what it does, to avoid the noise?

    Thank you very much

    ciao
     
  4. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,685
    Full Name:
    Mike 996
    I am suspicious of ANY change in the way something works. IOW, if the fuel pump WAS making noise (could it have been something else?) and now it is not, what changed? Mechanical things don't suddenly fix themselves...

    As noted, just turning on the ignition should not activate the pump IF your car has the switch mentioned and if it is connected. But...do all the cars have the switch regardless of model year/country? I don't know but I'm sure someone here does...
     
  5. are-jay-bee

    are-jay-bee Rookie

    Sep 11, 2012
    23
    Surrey, England
    Full Name:
    Robert Bruce
    I'm intrigued - where, how, what is this switch?

    Fuel pump on my car has always made the consistent humming noise when ignition is on. I'd presume it was broken if it didn't!
     
  6. Freddie328

    Freddie328 Formula Junior

    Jul 29, 2013
    291
    Herts, UK
    Full Name:
    Richard
    Presumably your car has Bosch fuel injection?
    If so, its on the back of the fuel distributor. The one on mines got a blue connector.Its there to switch off the fuel in the event of a crash or other errant action. I think a few people disconnect this safety feature, as It makes hot starting easier if the injectors/system have a leak.
     
  7. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
  8. DGS

    DGS Six Time F1 World Champ
    Rossa Subscribed

    May 27, 2003
    60,051
    MidTN
    Full Name:
    DGS
    #8 DGS, Apr 27, 2017
    Last edited: Apr 27, 2017
    I believe the QV is a bit like a 328: the fuel pump will only operate when the safety switch is open or the key is in "start".
    So the pump will only operate when the engine is running --- and, as Michael indicated, the pump doesn't run with the switch on and the engine off.
    (This cuts off the fuel pump if the engine stalls, so you don't flood the intake with fuel.)
    ("Continuous" Injection System -- but only continuous while there's intake air to go with the fuel.)
    You probably won't hear the fuel pump with the engine running.


    The "buzzing" you might hear with the engine running comes from the "frequency switch" in a CIS with Lambda.
    That gizmo (near the fuel distributor) is used with the O2 sensor Lambda computer to modify the fuel pressure in the CIS fuel distributor, to tweak the engine mixture.

    The car will run without the Lambda, but it will run rich.

    I have a US 328, so I can't help too much tracing the system on an Australian QV.
     
  9. ME308

    ME308 Formula 3

    Nov 5, 2003
    1,542
    Munich, Germany
    Full Name:
    Michael

    don`t worry ... yours is a carb car, isn`t it ? buzzing sound is familiar then ;)

    here we`re talking about 2V and 4V cars with Bosch K-jet fuel injection -
    on those cars the fuel pump doesn't see any voltage until key is in "start" position
    and that is when the fuel pump starts working
     
  10. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,212
    Black Forest Germany
    Full Name:
    Martin N.
    Like Michael already said; carbed Euro-cars have no built in failure mode things in the fuel supply circuit like switches and so on :)
    Ignition on ---> pump running.

    Best Regards
    Martin
     
  11. ntb308gtsi

    ntb308gtsi Karting

    Nov 17, 2013
    80
    South Africa
    Full Name:
    Nick B.
    Michael is spot on! I had the same experience, after having done some work on the car including injectors and fuel pipes the buzzing noise disappeared .
    I asked the ferrari shop that has just replaced my clutch about this and their explanation was almost verbatim Michael's!
    I can only conclude that with the work that was done when the injectors were replaced , the switch and fuel pump wires were disconnected and cleaned before reassembly and this rectified the problem. Probbably there was a bad connection before.
    Best,
    Nick.
     
  12. Transient

    Transient Karting

    Sep 6, 2007
    110
    Sydney Australia
    Full Name:
    transient
    Hi everyone,
    thanks for your replies, i will check the blue safety switch when i get home this evening and report back on Monday...
     
  13. Transient

    Transient Karting

    Sep 6, 2007
    110
    Sydney Australia
    Full Name:
    transient
    Hi everyone,
    i checked the blue safety switch over the weekend, all looks clean and connected and working as it should be.
    The car starts fine with no fuel pump noise before ignition.
    All pressures are good, operating temps are good, the car drives as it should.

    i think i will stop concerning myself with this issue.

    Thanks again for all your replies....
     

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