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Old 12-22-2008, 04:09 AM
Bill Wells Bill Wells is offline
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Join Date: Jan 2001
Location: Bloomfield Hills, (Detroit area), Mi
Cobra Make, Engine: Superformance 156, ex Paxton 351, now a 392 Ford Racing Stroker
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Dan Bevers ---------- years ago when I switched my old Ford ignition systsem to MSD, my tach did the same thing -----went up to 3k and then to zero while engine revs were still going up .

My mechanic called the MSD hot line tech support guys and we were told to add a MSD Tach Adapter ( I can't recall the MSD part number at the moment , #8910 comes to mind but i will continue to look thru records) .......a diode also had to be added after the Tach Adapter to smooth the tach out.

I recall in other experiences such as mine discussed some time ago that some folks with newer SPF's
had slightly different tach wiring and different alternator wiring which also affected Smith tachs differently on newer cars vs older cars like mine . Blas is the expert on what/when electrically . Bill

Bill
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