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Ozz1967 04-16-2012 12:54 PM
Jumpy Tach?
 
Hey guys,

84 T/A, 355, CC Qjet. Factory Distributor (138K miles), melonized gear for the roller cam.

The tach started jumping around today, anywhere from 500rpm to 1000rpm. At the stop light, when it jumped, it felt like the engine surged a bit. When gunning it and the RPM's going up, it'll jump and the car will feel like it's stuttering. Shorted plug wire? Bad dizzy? Any ideas?

Apeiron 04-16-2012 11:41 PM
Re: Jumpy Tach?
 
Misfire

Ozz1967 04-17-2012 06:53 AM
Re: Jumpy Tach?
 
Originally Posted by Apeiron (Post 5245579)
Misfire
That's kind of what I was thinking, just wanted to bounce some ideas around.

Ozz1967 04-17-2012 03:21 PM
Re: Jumpy Tach?
 
Originally Posted by Apeiron (Post 5245579)
Misfire
I pulled my cap off and found one of the rotor screws missing. It was down under the rotor and there were scratch marks all over the inside. Tightened it down and ranRit for fivea oe minutes, tach didn't jump. My guess is that it was shorting to the screw that was being tossed around the inside there. I also swapped in a different cap that I had from a spare dizzy that I had lying around. Hopefully it was that screw.


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