Wild Tacho

[rich71]

Hi all, if anyone can help in any way it would be great, my tacho has decided to have a mind of its own and goes wild on acceleration and takes a few seconds to settle back down afterwards.

Does anyone have any tips of what to check, it is an ECU2 1.6K 1997 supersport. I am also concerned that if it is at the sensor end then would this affect how the gear change light/rev limiter cuts in? Where does the tacho get its signal from initially before the ecu?

Thanks

Richard

[Markharrison2]

Let me know if you solve this I have a similar issue, although I have a slightly newer car, cheers

[Jonathan Kay]

... my tacho has decided to have a mind of its own and goes wild on acceleration and takes a few seconds to settle back down afterwards.

Do you think it temporarily underreads, or is it sometimes overreading?

My suggestions for investigating Mark's.

Jonathan

[rich71]

Jonathan, yes it probably does under and over read as the needle waves about or it may just under read and the max needle is what it actually is.

So far i have taken the Tacho out and given it a gentle shake and the needle moves freely, i can probably get it to read 4k by doing this as a guide, is it meant to?

I have also unplugged and reconnected the leads on the coil, haven't tried it since as started raining, in the garage it seems ok but it did before when stationary.

Richard

[Bricol]

On older cars I've had the same with a bad earth to the instrument.

 

[rich71]

I will check, just need to remember the multimeter from work

[rich71]

Quick update, seems unplugging and plugging everything back in has worked....

[rich71]

wobbly speedo also fixed by loosening the angle drive thumb screws giving it a shake about and re-tighten