328 Idle issue ... | FerrariChat

328 Idle issue ...

Discussion in '308/328' started by spirot, Apr 12, 2007.

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  1. spirot

    spirot F1 World Champ

    Dec 12, 2005
    14,532
    Atlanta
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    Tom Spiro
    #1 spirot, Apr 12, 2007
    Ok, I was having an idle issue on the 328 where it was kinda moving up and down ... and I thought I had an air leak.. so I replaced a couple of hoses.. and it got a bit better, but still was kinda acting strang... so I checked out the temp switch by taking a fuse and hooking it up to each lead as they go onto the temp switch... the idle seemed to settle down cause I'm bypassing the switch ... but what is interesting is when I un connect one of the wires I hear a little PSSSSST... like air escaping... from the AAV? what could this be.. the idle does not change... but just wondering what would cause this????

    this is more annoying than anything serious.
     
  2. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,940
    USA
    #2 f355spider, Apr 12, 2007
    What was the result of your test of the AAV? I seem to recall it did not close completely. I still suspect you need to replace it.
     
  3. spirot

    spirot F1 World Champ

    Dec 12, 2005
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    Tom Spiro
    #3 spirot, Apr 14, 2007
    no, its closing according to spec... after I cleaned it up it works well... I dont think is the physical operation of the AAV.. electrical maybe?
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,151
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #4 Steve Magnusson, Apr 14, 2007
    Your message seems somewhat contridictory -- first "the idle seemed to settle down" and then "the idle does not change"? -- but don't do this on a US version 328! When you short the water temp switch "closed", this turns on the air injection system -- which will cause the O2 sensor to read the exhaust as very, very lean, and the injection ECU will drive the frequency valve to add more fuel (and when you unconnect, it turns the air injection off and this maybe is related to the noise you are hearing).

    Is the warm idle any different with the O2 sensor plugged in vs unplugged? -- shouldn't be.
     
  5. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
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    Sam
    #5 sammyb, Apr 14, 2007
    Have you hooked the engine up to a smoke machine to test for vacuum leaks? When I hooked up mine, it turned out the two tiny and short hoses underneath and to the rear of the plenum were leaking (one was totally disconnected.) I suspect you still have a leak or two somewhere.

    There are many hoses around the car -- all of which are prone to cracking from heat and age.
     
  6. wberner

    wberner Karting

    Aug 17, 2010
    53
    MA
    Full Name:
    Wade
    #6 wberner, Feb 10, 2019
    I know this is an old thread, but can you give me some direction on where you connected the smoke machine to test your vacuum? Much appreciated.
     

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