AAV Wiring | FerrariChat

AAV Wiring

Discussion in '308/328' started by surfdwn, Jan 30, 2022.

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  1. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    I have been chasing down why my 328's idle stays too high after initial startup. I comes down very slowly as the car warms up, but takes way too long to come down.

    I took the AAV out yesterday and tested it by putting it in a bag in boiling water and it closed completely. I then put 12 V on it and it closed in 2 minutes, so the AAV is OK.

    I measured the voltage and resistance at the AAV connection this morning. With the ignition ON, I got no voltage on the connector. Neither pin showed grounded or voltage. One of them should have been ground.

    Looking at the wiring diagram, it looks like the AAV, fuel pump, and WUR are all supplied by the same wire and the other components appear to be all working OK.

    Does anyone no the routing of the wires from the AAV? I think I must have a broken wire or bad connector at some point, but have am not sure of the cable routing. Any suggestions?
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,106
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #2 Rifledriver, Jan 30, 2022
    Last edited: Jan 30, 2022
    There is a black and as I recall a beige wire, black being ground. The black wire goes straight to a chassis ground according to the diagram. It should be close to the coolant tank.. The beige wire goes to connector 169 next to the oil cooler and daisy chain's to the fuel pump. If the pump is running the beige wire should be hot. Near as I can tell the ground only serves the air valve.

    I didn't trace it that far but your power wire is probably switched by the air flap switch on the CIS distributor so simply having the ignition switch to on will not give you power. Unplug the blue connector on the fuel distributor and try your power at the AAV plug again.

    When I am working in that area I disconnect the overflow hose, the 2 air hoses, unbolt the coolant tank mounts, disconnect the wires to the thermo switch, the AAV plug and lift the coolant tank with water hoses connected and lay it forward upside down up towards the oil filter. Then you can actually see things.
     
    Saabguy likes this.
  3. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    Thanks so much. I had determined that it was the beige wire, but had not tracked down the air flap switch. My problem my be at that connector at the oil cooler. Your comments will point me in the right direction!
     
  4. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    I can't seem to find the air flap switch on the wiring diagram....
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #5 Steve Magnusson, Jan 30, 2022
    Last edited: Jan 30, 2022
    Item 72 in Fig 2 of the 440/86 328 wiring diagram. Unplugging it with the key "on" leaves relay s unenergized which allows the +12V signal from (closed with key "on") relay u to pass thru relay s and close relay r and run the fuel pump, AAV heater, WUR heater, etc. (with the engine not running).

    The 440/86 wiring diagram shows no connector between the fuel pump and the AAV -- so if the fuel pump is running, but you have no +12V power on the P (beige) wire at the AAV = must be some sort of bad wiring connection at the fuel pump terminals.
     
  6. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    Thanks! I will check it out!
     
  7. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    I pulled the connector at the air flapper and measured the voltage at the AAV. I got 12 volts, so I cleaned up the AAV connector and put everything back together. The car started right up and now idles correctly as it warms up. Thanks to everyone for the sage advice!
     
  8. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,106
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    If all that was really done was to pull and reconnect connectors it was probably a matter of corrosion which does happen to them. Get some contact cleaner and an old tooth brush and scrub them some.
     
    Saabguy likes this.
  9. surfdwn

    surfdwn Karting

    Sep 28, 2005
    140
    Freeport, Fl
    That is what I did before reconnecting them. There appeared to be some oxidation on the connectors, so I got out the contact cleaner and had at it.
     

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