Wierd Tach problem after MSD install
Thread Starter
Racer
Joined: Apr 2004
Posts: 298
Likes: 1
From: Springfield Missouri
Wierd Tach problem after MSD install
I got a Digital6 box installed, and for some reason the tach won't go above 3K.
The car runs fine, the tachometer reads correctly below 3k, but as soon as I get after it a little and the needle gets up there, it falls to zero and lays still untill actual RPM is back below 3k
strange, huh?
The car runs fine, the tachometer reads correctly below 3k, but as soon as I get after it a little and the needle gets up there, it falls to zero and lays still untill actual RPM is back below 3k
strange, huh?
Pro
Joined: Jan 2004
Posts: 503
Likes: 0
From: Forney Texas
I wish I could tell you how to fix your problem. I am currently experiencing the exact symtoms with my 90 L98. I plan on bringing the wiring diagrams for both the aftermarket ignition system and the diagrams from my factory service manual to our electrical engineer at work. Hopefully, he can at least point me in a direction to start. I will post what he comes back with in a few days.
90Indy
90Indy
Racer
Joined: Aug 2005
Posts: 336
Likes: 3
From: State of Confusion
I had this exact same problem trying to use the MSD Blaster HEI coil, the tach would wig out between 3500 and 3750. There is some kind of radio interfearance issue. The other thing that I found out is that this radio interfearance also tweeks the signal going to back to computer, which therefore tweeks the signal going out to the distributor to advance the timing under acceleration! I wound up installing a new factory coil and it went away. MSD does make a tach fix, don't know if it works or not. Their other suggestios sure didn't work.
Keep the rubber side down,
Adam.
Keep the rubber side down,
Adam.
Racer
Joined: Aug 2005
Posts: 336
Likes: 3
From: State of Confusion
Originally Posted by hookedup
Do a search for tach filter bypass, that should fix your problem.
Dave
Dave
Le Mans Master
Joined: Feb 1999
Posts: 9,936
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
Originally Posted by MATCHLIGHT
You don't have to do a search, pick up the phone and call MSD and tell them what your problem is. They will send you the tach fix for free, they sent me one. Whether or not it will work for you is a different story.
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Racer
Joined: Aug 2005
Posts: 336
Likes: 3
From: State of Confusion
Originally Posted by steve40th
I posted that question last year and nobody said a thing.
