400i Alternators, and ignition timing | FerrariChat

400i Alternators, and ignition timing

Discussion in '365 GT4 2+2/400/412' started by timthetooth, Jan 17, 2007.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. timthetooth

    timthetooth Rookie

    Dec 18, 2003
    33
    Hi Guys,
    The top alternator in my 84 400i failed recently, the warning light illuminated with the ignition off and key out, and went out with the key turned ready to start(when the light for the lower unit came on as it should).
    Is this something that could be repaired, or am I better off with a new alternator. If its a new one, is there another source other than ferrari, I am in London UK.
    Next, I have set the ignition timing to the stock 8degrees BTDC and the car runs smooth, but if I advance it a bit I get more power all round. I am using 100 octane fuel and get no pre detonation , has anyone got any info on how much advance you can use. The car is an auto, so the engine never really labours as it could with a manual, so it is difficult for me to assess if it is pinking or not.
    Regards,
    Tim.
     
  2. 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
    Before advancing the static idle timing, you should verify that the advance mechanism inside the distributor is quasi-working as intended IMO. See page 75 of your OM for the specs [although the chart and the text don't agree -- the chart says 27 deg total at crankshaft 5000 RPM (8 + 2 x 9.5 = 27) while the text has it as 30 deg total -- my guess is that they wrongly reused the chart from the BB512i OM which has 10 deg static + (2 x 9.5) deg at 5000 RPM crankshaft = 29 deg total and that does match the corresponding BB512i OM text]. In any case, it should be adding a lot of advance quickly at the low end in the 1200-2000 RPM crankshaft range, so, if it isn't, this might be rather noticeable in normal driving. Do you have 22 year old grease inside your distributor, or has it been serviced/checked more recently? ;)

    Nothing special about the alternator -- have it rebuilt (no need to buy "new").
     
  3. Timp

    Timp Rookie

    Oct 8, 2005
    42
    My mechanic just put an Audi alternator into my 1978 400. I only have one alternator. It made a world of difference, charging I think he said at around 75amps vs. 35 ish. I don't have the specs but am getting them in a week or so and will share them on a thread going on right now called 'sea foam green'

    cheers, Timp
     

Share This Page