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Registered
Join Date: Sep 2002
Location: Tulsa, OK
Posts: 134
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perma tune question
should the perma tune cdi unit make the same high pitch whining noise as the stock unit?
thanks, dlg |
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08-03-2003, 01:51 PM
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Registered
Join Date: May 2001
Location: Peoples Republic of Long Beach, NY
Posts: 21,140
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my 3 pin model never whined that I could hear.. Warren said you could hear a whine with a sound probe...........Ron
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Ronin LB '77 911s 2.7 PMO E 8.5 SSI Monty MSD JPI w x6 |
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08-03-2003, 02:08 PM
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Crusty Conservative
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Heard somewhere they made a kind of sucking sound...
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Bill 69 911 T Targa, 2.4E w/carbs (1985-2001) 70 911 S Coupe, 2nd owner (1989- 2015) 73 911 T Targa, 3.2 Motronic (2001- ) |
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08-03-2003, 02:17 PM
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Registered
Join Date: Jun 2003
Location: St Petersburg, FL
Posts: 3,814
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My permatune is silent for all I can tell, then again the rear fuel pump in my 930 makes quite a bit of noise that is hard to compete with.
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08-03-2003, 02:18 PM
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Registered
Join Date: Dec 1999
Location: TX USA
Posts: 9,804
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The early blue-anodized Permatunes did whine just like the Bosch CDI-units, but the latest-model, clear-anodized units are potted internally with epoxy ... and the sound is muted considerably, though a mechanic's stethoscope can still reveal the normal operation of the DC-to-DC inverter oscillations.
There are several failure modes for the Permatune units ... not related to the DC-to-DC inverter! Some are heat-related, as Ron can attest ... A good Tektronix oscilloscope is the best troubleshooting tool for CDI & Permatune testing ... though a Sun Analyzer at a shop is a good tool for gleaning whether ignition performance is up to snuff, too. All electrical system parameters must be normal ... before CDI-systems can be narrowed down as the culprit. That means good, clean grounds at the battery, relay/fuse/CDI panel, alternator, and transaxle ... are a prerequisite!
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Warren Hall, Jr. 1973 911S Targa ... 'Annie' 1968 340S Barracuda ... 'Rolling Thunder' |
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08-03-2003, 02:25 PM
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1970 Porsche 911S 2.2l MFI
