Tach bouncing and spiking when accelerating

[Utah240zOwner]

Hi Everyone,

 

I jumped in my 240 the other day and as soon as I fired it up I saw smoke come from the dash. Now my tachometer bounces at low Rpms and spikes instantly as soon as I touch the accelerator.

 

Any thoughts?

 

Appreciate the help!

 

Arturo

 

 

Sent from my iPhone using Tapatalk

[Pilgrim]

A very simple thought: you may have melted a wire or connection. The first thing I'd do is get under the dash on the driver's side with a strong flashlight and start tracing wires, looking for evidence of burned or melted wires or connections. I would devote specific attention to the back of the tach.

As the electronics guys would say, you have released the magic smoke that makes the electronics work. 

[Zed Head]

2 hours ago, Utah240zOwner said:

I jumped in my 240 the other day and as soon as I fired it up I saw smoke come from the dash.

More details about the car would be good.  The obvious thing is a damaged tachometer though.  Some sort of internal short.

 

[Jeff Berk]

Just a thought, you might want to disconnect, clean, and reconnect each connection while you go through the wiring. Almost all my electrical issues on my car seemed to trace back to bad connections.