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Registered
Join Date: May 2004
Location: Iron Mountain Mi. summers& Fort Myers winters
Posts: 80
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Tachometer failure
In checking continuity between the TD terminalon the tach on my 80 911 and the CDI TD terminal, I found that it appeared to be open. I also found that the TD terminal on the CDI to ground also showed open. Could the CDI have only failed in that one section of the circuit board. The car starts and runs fine, just no tach signal.
Thanks Chuck
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Chas |
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07-02-2007, 06:17 AM
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Registered
Join Date: Dec 1999
Location: TX USA
Posts: 9,804
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If switching diode D8 - 1N4148 blows ... all you lose is the TD tach signal. Look at the last pic at the end of this thread:
6-pin SC/Turbo CDI unit repair documentation
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Warren Hall, Jr. 1973 911S Targa ... 'Annie' 1968 340S Barracuda ... 'Rolling Thunder' |
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07-02-2007, 07:56 AM
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Registered
Join Date: May 2004
Location: Iron Mountain Mi. summers& Fort Myers winters
Posts: 80
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tachometer failure
Warren,
Thanks a lot for the info on the circuit board. That really does help in troubleshooting this problem. If D8 is okay, what kind of signal should I be seeing out of terminal TD, and shouldn't it vary with the speed of the engine? Thanks again Chuck
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Chas |
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07-02-2007, 09:39 AM
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'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
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07-02-2007, 10:43 AM
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