When I stomp on it or rev it up the tach only goes up to 3000 and jump back down and up , but no higher. What up with that can anyone help.

 

Hello com'on someone must be able to help me. Is the wire grounding out?

 

I'll take a shot. First, is it a stock tach or an aftermarket one? If it is aftermarket I'd check the wiring.

One thing that can make tachometers jump around is electrical interference. Check your spark plug wires(and the one going to the ignition coil) for any kind of cracks, burns, etc. Even if you don't see anything wrong with them, plug wires degrade over time and become less efficient. If they need to be changed, I would go with spiral core wires, not solid core. Also check your distributor cap for any signs of damage.

If you're running a high-end stereo with an amp, you may want to check the routing of the wires and their condition as well.

Hope I've been of some help.