Tacho going a bit mental when thins such as lights are swiched on
Turbo Mini Forums

The mini after running very well for 3 years has decided to begin being a bit of a pain in the arse (also taking into account the oil pressure thread)

I seem to have a problem that when I drive either with the lights, heater, or both on The tacho dances about, and you can feel the sparks getting fired out of sink, but corresponding to whichever position the tacho is in.

The problem is worst at 3000 rpm where the tacho needle will be dancing round to 3500 or more.

I am wondering if there is a bad earth somewhere, but what else could it be?

Thanks
James

Edited by minimole23 on 20th Dec, 2008.

coil earth will be a good place to start.

the way it is doing it with the lights/heater on i would say check your main earths, so boot earth, and engine earth.

take them off clean them up and try it. any sort of earth that connects the things that seem to effect it.

Hi,
Sounds like a poor ignition feed, check for poor connections on the white and on the green wires on the fusebox
Also the fuse and it's connection in the fusebox.
Cheers,
Gavin :)

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today I went through all the earths and also had a play with the fuse box and around the coil area.

here is a video of the problem, it doesn't occur below 2000 rpm or above 4000.

any thoughts welcome, this is pissing me off as I want to go out tonight, but don't want to fuck anything by driving it.

here is a video (the fixed version)

Edited by minimole23 on 20th Dec, 2008.

i'd have gone with the above of earth straps or live feed to the coil but considering your comment below, could be HT leads? and sorry, couldnt veiw the vid, didnt work for me

I've changed the ht leads, I will go and take the ignitions system apart and see where things go from there and report back.

Don't look like i'm making it out now at all

My tacho goes crackers when I indicate to turn right.

I know what the problem is. The printed circuit board at the back of the instrument pod has been repaired but there is an earth leak. So the tacho signal gets earthed when the turn indicator in the pod operates.

Might just be worth checking the connections at the back of the pod.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I've had enough of this, now the starter motor has just died I think.

i have just been through the whole electrical system, changed the fuse box, changed the coil, double checked the earths and checked for damaged wires.

Anyone else not get tempted to set fire to their car occasionally?

time to change the starter motor and then the distributor then I'm out of ideas.

Have you checked that your battery is good and the alternator is putting out enough volts?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Fixed it. I changed the ignition module as a last resort and it seemed to have worked. no problems now.

Though the starter motor is broken, will put a picure up of the damage to that.