308 Digiplex failure on hot days | FerrariChat

308 Digiplex failure on hot days

Discussion in 'Technical Q&A' started by kdross, Aug 15, 2005.

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  1. kdross

    kdross Formula Junior Silver Subscribed

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    Ken
    Has anyone experienced a failure of their digiplex units on a 308 during really hot days? I drove my car this past weekend during 98F heat with 90% + humidity and one of my digiplex units crapped out. For whatever reason, my 1985 308QV started to back fire and the engine died during a long drive this weekend.

    Also, I have lost the Word document on grounding a digiplex. If someone has this article would you be so kind to email a copy to [email protected]. Thanks.

    Ken
     
    kdross, Aug 15, 2005
    #1
  2. 4redude

    4redude Formula Junior

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    Ken, there is a Service Bulletin regarding this anomoly. There is a "protection diode" to install. The SB describes how to install, and includes a wiring schematic. The diode is less than $10. Call or e-mail tomorrow and I will be happy to check stock and fax you the SB. 800-233-7820 or [email protected]
     
    4redude, Aug 15, 2005
    #2
  3. dave80gtsi

    dave80gtsi Formula 3 Silver Subscribed

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    This is the first that I have heard of hot weather Digiplex problems. What's the deal here? Which cars / models? What's the symptoms? What's the fix? Etc. Etc. Etc.!

    An ounce of protection is worth a pound of cure, and all of that jazz.

    Thanks and Cheers - DM
     
    dave80gtsi, Aug 17, 2005
    #3
  4. 308GTS

    308GTS Formula 3

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    How does the protection diode solve this? From what I understood the protection diode was to keep the 02 sensor from sending V backwards toward the lambda control unit.
     
    308GTS, Aug 17, 2005
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  5. Jeff Pintler

    Jeff Pintler Formula Junior

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    A while back someone posted about TDC or rpm sensors getting hot and opening-up (failing) and then would work fine when cool. Fwiw

    Jeff Pintler
    89348tb, 86tr
     
    Jeff Pintler, Aug 18, 2005
    #5
  6. dave80gtsi

    dave80gtsi Formula 3 Silver Subscribed

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    If a sensor fails, then is this what is really meant bythe "Digiplex Failure" comments earlier in this thread?

    Still scratchin' the ol' head on this one.
     
    dave80gtsi, Aug 18, 2005
    #6
  7. enjoythemusic

    enjoythemusic F1 World Champ

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    The only service bullitin i see is on page 161 and titled SB 80-13 dated 8-5-82 and concerns the Mondial 8 and 308 GTBi/GTSi up to S/N 41753.

    It basically is a recall/replacement to avoid EMI. If your digiplex has a red dot on the upper left side the update was done. Also, you may want to add a grounding strap to chassis to insure a good grounding of the boxes.

    They also STRONGLY SUGGEST not to connect ANYTHING (cell phone electronics, Alarm system, etc) to the boxes power or ground.
     
    enjoythemusic, Aug 18, 2005
    #7

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