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Rootsy
08-15-2001, 03:09 PM
I encountered a rather strange phenomenon i havn't seen before, and i;ve seen some strange stuff... swapped the Tbolt V module for the IV and now from 3 to 4000 rpm the tach will jump erratically... engine isnt missing. Figured maybe i had a loose connection on my signal wire but nope all is fine there... wondered if the shift interrupter was bouncing so i put her in gear and unplugged it.. made a run and sure deal it was gone... have no issues with the interrupter working at all, everything shifts peachy.. never had this happen with the TBolt V. So i figured it was wehre i plugged it into the new harness for the new ignition module so i put a new bullet connector on it... all was fine for bout 5 minutes of run time.. then it's back... everything is crimped and sealed and tight... all my other connections are fine. i rev it up bout 3 grand, let it sit at speed wiggle wires and the interrupter switch etc etc... can't make it happen... rev it up again... it's back by itself, put a timing light on it and you can see the timing jump once in a while at high rpm ever so slightly. the tach almost looks like it's hitting a rev limiter.. least that is the needle action, but no rev limiter so no worries there... anyone else encounter this before? can't be the first time it's ever happened. funny thing is i peg her and wind her out to 4500 rpm and it is steady as a rock only happens in that 3000 - 4000 rpm range. Somewhere Something is interferring with my tach signal and distributor signal according to the timing light... maybe the module inside of the distributor? any thoughts? anyway, sorry to be so long winded, if you have ideas please... fire away eh...

Thanks!

Root

avanti
08-16-2001, 07:21 AM
On our 2000 Donzi 18 Classic with a 350Mag in it we encountered the same problem. We contacted the Gaffrig dealer and they sent us a filter to go on the back of the tach and this cured the problem.