Guage Prob??

[SuperStanger101]

I have an Autometer Tach, and it started to act up. It now reads DOUBLE what the true RPMs are at. Now it's obviously hooked up still because it moves but what could be making it read double?? (I also have an MSD 6AL box, which the rev limtier chip keeps sliding out of. When I put it back in, the tach still reads double, not sure if that has anything to do with it.) Anyone know whats going on or how to fix it? It would be greatly appreciated.

 

[Camman]

Is it a guage that is for 4/6/8 cylinder engines? Sounds to me like you have it on the 4 cylinder setting. Usually there is a wire that must be disconnected, but consult your instruction manual on how to change it.

 

[hllon4whls]

That sounds about right. Possibly one of the wires opened up causing the tach to read the 8 like a 4. Autometer should have all the info needed on their website. MSD certainly does. The chip in the msd only does the rev limit. I have never heard of these chips sliding out. Mine is extremely tight and is a a few years old.

 

[Foxfan88]

my old sunpro minitach had the adjustment on the back of the tach

 

[Black1987Stang]

haha my tach does the exact same thing, it used to only do it a few times and when it did i could smack it and it would go back to normal but now it does it all the time and it sucks lol i had the thing totally apart and still cant find anything wrong with it. to switch to a 4, or 6, cylinder u need to cut a certain colot wire thats sticking out in the back of the tach, but i still cant find anything wrong with anything o well JUST FOR NOW im using my stocker tach

 

[89MustangGX]

Some of the gauges do have an actual switch. I would imagine if you have been cleaning or around the back of the gauge you could have slid it over. Worth looking into...

 

[SuperStanger101]

Nah, there's no switch. It's an Autometer Sport Comp Silver tach. You have to cut a certain wire on the back for 4 & 6 cyclinder applications. I looked at their docs and spoke to tech support. It's either a loose solder connection or something else internal. They say I should mail it in for service.

Thanks to everyone for their replies and help on this issue!