tachometer wierdness Isuzu 157

[coolchange]

Hi all...I have an Isuzu 157 engine and the tachometer problem started just this last trip..tach bouncing both above and below...mostly above the actual rpm by 2-8000 rpm

It is clear that the engine (6cyl Isuzu diesel) is not surging or falling off at anytime during this bouncing.

I looked at past threads and see that I need to check wires for corrosion...anyone able to head me toward the correct location of the sender on this engine...

You can save me a lot of "upside down" time hanging over the engne and it will be appreciated.

any and all help appreciated.

[Jay Knoll]

Follow the grey wire from the tach thru the harness to the engine (that is if they were using current color codes)

Sorry that's all I've got, I just checked my engine manual, nothing about the wiring there

I had a similar problem, all my guages going crazy, it was a bad ground (actually a series of bad grounds, but now they're all at one point