328 loss of power | FerrariChat

328 loss of power

Discussion in 'Technical Q&A' started by tfrancis, Aug 10, 2010.

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  1. tfrancis

    tfrancis Karting

    Nov 3, 2003
    93
    Memphis, TN
    The past couple weeks I've been trouble shooting a problem. Fortunately I've figured it out but thought I'd pass on what I've learned. Let me first state that I'm an engineer but not a mechanic... much less an expert at electonics.

    I noticed that I had what seemed to be about half the power I normally get from my 328. I first checked my spark plugs and noticed they did need to be replaced. So I replaced them and also inspected the extensions which looked good. Started the car but no change.

    Next I checked for vaccuum leaks and noticed two hoses had come loose from the "Air delivery pipe" under the plentum. I removed the oil filter and a couple hoses so I could get my hand inside. It took patients and I got everything hooked back up but didn't solve the problem.

    I asked a more knowlegable friend of electrical systems who started by checking the TDC sensor then the Angle rotation sensor which both check out fine. Next we focused on the Electric Ignition Module. I swamp mine out with a local friends 328. No change. Good thing too since it's over $3K to replace. The vaccuum line also check good.

    An engineer at work suggest I check to see if the wires were getting spark by attaching a timing light. Probably should have been one of the first thing I checked. I went home and hooked up the timing light and the front bank worked fine. Hooked up the back bank and nothing going. Now I was on to something. I hooked up the timing light behind the distributor to see if it was getting power. No dice. That was good to know since distributors cost $500. So the problem was now looking like the ignition coil or power module. I decided to switch power modules to see if this would give spark to the back and it sure did. I ordered the part from T. Rutlands for about $130. I got the part installed and my car lunged with power like a Ferrari should!!

    Here's a pic of the new power module. I've got more pictures I'll post soon.

    Tom
     
  2. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    Nice job Tom, sounds like it was basic diagnostics...fuel, air and spark! ;)
     
  3. tfrancis

    tfrancis Karting

    Nov 3, 2003
    93
    Memphis, TN
    #3 tfrancis, Aug 10, 2010
    Last edited by a moderator: Sep 7, 2017
  4. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    7,782
    Full Name:
    Sparky
    Don't see a pix but could have just been corroded connectors. Not unusual and a clean-up can usually solve the problem.
     
  5. tfrancis

    tfrancis Karting

    Nov 3, 2003
    93
    Memphis, TN
    #5 tfrancis, Aug 10, 2010
    Last edited by a moderator: Sep 7, 2017
    Here is the power module installed. Also a pic of working with the plug attachment. Make sure to care when releasing the outer clamp ring. You need to release it to unplug from the power module. Make sure the ring is in place prior to plugging back into the module.
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  6. tfrancis

    tfrancis Karting

    Nov 3, 2003
    93
    Memphis, TN
    True.... I checked this out but no luck in my case.
     
  7. Robz328

    Robz328 F1 Veteran
    Silver Subscribed

    Mar 16, 2009
    6,290
    ATL, Georgia
    Full Name:
    Rob Hemphill
    How many patients did it take (I need to know this since I will be working on my injectors soon and need a benchmark). :D:D

    BTW, excellent troubleshooting!!!
     
  8. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,238
    Frederick, Maryland
    Full Name:
    Brian Brown
    Good for you! Most people don't know the importance of applying the heat sink compound to the bottom of the unit. Should last a long time.

    Brian Brown
    Patrick Ottis Co.
     
  9. Joe G.

    Joe G. Formula 3
    BANNED

    Dec 9, 2003
    1,109
    Los Angeles
    Full Name:
    Joe Gazzani
    tom francis ?
     
  10. tfrancis

    tfrancis Karting

    Nov 3, 2003
    93
    Memphis, TN
    Hi Joe.... this is Tom in Memphis.
     
  11. eulk328

    eulk328 F1 Rookie

    Feb 18, 2005
    2,800
    Full Name:
    F683

    It should be pointed out that even people that do know about applying heat sink compound often times put too much compound on the parts which can defeat the purpose of it. I've seen it often.

    In the photo above, the amount looks excessive. It should be the minimal amount possible while covering the entire surface. As thin a layer as possible.
     
  12. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    2,149
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    Absolutely correct post. The purpose of the compound is to fill the air gaps between the two parts. Air has a low thermal conductivity so it acts as an insulator between the portions of the two objects that do not touch. The thermal conductivity of the compound is much greater than air so when it fills the gaps, the total heat transferred is greater than what it would be with air gaps. However, if one applies too much of it which would then keeps the parts separated, the overall thermal resistance to heat transfer increases. This occurs because the thermal conductivity of the compound is not infinite.

    Without the compound heat is transferred to the air in the gap, then it conducts through the air in the gap, and finally reaches its destination. Heat is also transferred directly across the gap via radiation but this is slight at low temperatures when compared to what is conducted through the thin air gap. Filling the gap with heat transfer compound is less of a resistance than air plus radiation in parallel. But if you apply too much compound, you are adding resistance to the system.

    The compound is not designed to act as a sink. Its purpose is soley to lower the contact resistance of two objects with the object receiving the thermal energy being the sink.
     
  13. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
    2,345
    They are abundant at the ER clinic on Saturday nights.

    Re the heat sink grease...+1 with Larry and Gene on not over doing it. It's a finesse thing not a lubrication process and is to overcome not having perfectly machined surfaces. Too much is worse than none.
     

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