3 replies to this topic

[mini1976]

Ive recently noticed that somthing weird is going on with my ignition system. When driving around town in 4th and i put my foot down to accelerate the revs ( on the counter) suddenly jump from about 1500 to 3000 but with no increase in engine speed infact it judders a little and then the revs ( on the counter) drop back down to 1500 ish and I accelerate away. Ive also noticed it do a similar thing when at about 3000 rpm and i accelerate the rev counter shoots upto about 4500 and then drops back down to 3000 ish as the engine accelerates. The engine is a mg metro 1275 with electronic ignition and the rev counter runs off the coil.

Can anyone give any advice about what might be causing the rev counter to over read by about 1500rpm in both cases? Any help would be great as I really have no idea what could be causing it. I replaced the ignition module (the little black box on the side of the disributer) about 6 months ago.

Any suggestions?

[Wil_h]

I'd guess that the ignition module is faulty, but you say you changed this.

Is the ignition module supplied with 12V? It's just that a lot of people get the supply from the +ve of the coil on a mini, and invariably this is 9V rather than 12V because of the balast resistor. At 9V the modules don't always work properly. Worth checking.

[minimanclive]

I've found from my own experience that when the rev counter goes mad the the ignition coil has been the cause of the problem.

[mini1976]

Thanks for that I'll have a look for another coil and see if that solves the problem. I hope so as the ignition moduels are a touch pricy at 30 quid a pop. I was told they have to be new ones as you cant get the heat conductive grease except with a new one. Is that true? Or can I try a know to be working second hand one?

Thanks for the help guys