Few fuel issues that i cant resolve

Discussion in 'Technical' started by mijake, Nov 11, 2008.

  1. mijake

    mijake Member

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    Hi guys,

    I have 3 fuel issues that I cant figure out. Firstly are 2 that I have had for a long time now.

    Whenever I start the car when cold after the car has been sitting for a few days without being used, the car starts instantly but overrevs to just over 2000rpm for an instant then settles back to normal. This does not happen when you leave the car for just one day. Only happens after a few days of no driving.

    The other ongoing problem i have is everytime that I fill the car up with a petrol at the servo, the car struggles to start. It helps with a little accelerator. I never had starting problems any other time. I have heard people having starting problems when turning the car off for 5min when the car is warm and having problems starting it again but I dont have that problem. I dont have problems cold starting except for the prroblem stated above. The problem only ever occurs after filling up petrol.

    If you have read this far, thanks! The last problem is a recent problem I have encountered. I went to the track this time and after a session of a few hard laps, when pulling back into the pits, when i turn the car off, I can hear a loud buzzing sound coming from the fuel tank. The noise only goes away when i remove the fuel car and relieve the pressure from the tank. I also noticed that is I went for a warm down drive around the block or so for 10mins, the buzzing disappears. I have a feeling its to do with pressure build up in the tank or something, can anyone point me in the right direction.

    Any hints to the problems would be greatly appreciated!

    Thanks
    Michael
     
  2. WazTTed

    WazTTed Grease Monkey

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    sounds like your fuel pump is on the way out mate...

    time for a new one!


    as for the high rev. that's actually quite normal . as long as it comes back down within a second or so...
     
  3. red32

    red32 You talkin' to me?

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    Disagree!

    The fuel pump activates as soon as you turn the ignition key to 'ON' to start the car, and continues to pressurise the system after you turn the ignition to 'OFF'. Runs for about 20-30 seconds
    This is the buzzing sound you can hear.

    As to why your car is hard to start after filling with fuel, I have NFI!
     
  4. mijake

    mijake Member

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    Thanks, but the difference i can hear is a very loud buzzing noise. Normally when i drive and switch the car off I do hear the pump still running for a few seconds afterwards but the loud buzzing only happens after the car is run hard i.e at the track. Could it be something to do with over pressurising?

    Mike

     
  5. mijake

    mijake Member

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    anyone have any other ideas?

    im struggling to think of what could be causing the 3 symptoms
     
  6. WazTTed

    WazTTed Grease Monkey

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    if you can hear the pump buzzing when it shouldnt be. and are having dramas starting. your pump is dying. they buz when they die.! get a new one mate!!
    remember it is over 20 years old !
     
  7. 300zxt

    300zxt Well-Known Member

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    Negative.

    Older fuel pumps get noisy sure, but just because it's buzzing doesn't mean it's about to die. I've seen pumps do this for years, still not failing. Some 800HP+ high flow pumps off the shelf are noisy as hell. Plus that's just a simple guess, the smart thing to do would be to check the fuel pressure and see if it's pumping adequately.
     
  8. heavytrevy

    heavytrevy "Hammer time "

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    My pump was extremely noisey, but worked fine . I only replaced as a precaution for a very long road trip (4500klm).
    I don't miss the buzzing either lol :zlove:

    Trev

     
  9. mijake

    mijake Member

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    Thanks for that, checking fuel pressure sounds logical.

    Is it possible to have too much pressure in the fuel tank? Im thinking about this is cause the buzzing goes away when i relieve the pressure from the tank.

     
  10. mijake

    mijake Member

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    Sounds valid but I have had a pump die on another car and the sound that made was completely different. Also I find it rather hard to believe that my dying pump will cause me to have starting problems only when I fill up new fuel. Maybe the new fuel is cold and gives my pump the shivers. haha. But seriously I dont think thats the cause. I have been driving around for 7 years now with my pump doing what it has been doing all this time and with many spirited drives and not once running lean enough to pop my engine I find it hard to believe.

    The only symptom that is new is the loud buzzing after a hard run at the track that goes away after a warm down drive.

     

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