13 replies to this topic

[minicrystal13]

hi guys and gals need some advice please.

 

recently only sometimes when I turn off my mini it sometimes turns off straightaway but in a split second the engine kind off jumps and stalls, my brother thinks it may be the coil on its way out but was wondering if any off you may of had this experience or any ideas what could be causing this.

 

Thanks  Sam.

 

[Spider]

It's not Running On a tad is it? That's when it seems like the ignition is still in the run position though will usually on Run On half to two revs only. It happens for a few reasons, common ones are following a head service, if the head was skimmed but not de-bured there can be thin, sharp bits of cast irn left in place which get hot (very hot) during normal running and work like Glow Plugs when the engine is switched off with the key, and are hot enough to keep ignitng the fuel when it gets compressed (as part of the normal running cycle of the engine).

 

Another cause with similar effects can be from running excessively rich and the combustion chambers become carbon coked and the same thing occurs, though I would doubt it would be from this.

 

Excessively lean mixtures can do the same as again they burn super hot and heat up the thinner edges within the combustion chamber, though this is also usually associated with hot running (on the temp gauge).

 

Too much Ignition Timing can also have the same effect and for similar reasons.

 

None of these are good and can lead to serious engine damage. Have it sorted.

Edited by Moke Spider, 14 June 2015 - 05:23 AM.

[mab01uk]

Later Mini's were also prone to this due to lower quality fuels and leaner mixtures for emissions, so Rover fitted an anti-run on valve which can be seen mounted on the servo bracket on earlier pre-injection Rover Coopers, etc 1990-91 with carbs. (Also fitted to some A-Series Metros)

 

Item 61:-

http://www.somerford...age=page&id=175

Edited by mab01uk, 14 June 2015 - 06:12 AM.

[Dan]

Pretty much the only thing it's definitely not related to is the coil! As above its caused by hot spots in the compression chamber which in turn are caused by all sorts of things, if it's something it has just slowly started to do by itself it's likely to be due to carbon build up in the head.

[carbon]

Next time the petrol tank gets low try filling up with Shell 99-octane. It's a bit more than standard grade petrol but the chances are it will cure the running-on and also you may well find that the car runs better.

[bob540]

I had this a while back, had the timing adjusted and it sorted it, has slowly started to come back again now though so I think it needs adjusting again.

[CityEPete]

I had this a while back, had the timing adjusted and it sorted it, has slowly started to come back again now though so I think it needs adjusting again.

Get an electronic ignition kit, fit, time the ignition and forget it forever   If anyone says "yeah but what if it fails and dies without warning" (which I have only had happen with points and condensers!) buy two and leave one in the glove box!

[bob540]

I had this a while back, had the timing adjusted and it sorted it, has slowly started to come back again now though so I think it needs adjusting again.

Get an electronic ignition kit, fit, time the ignition and forget it forever   If anyone says "yeah but what if it fails and dies without warning" (which I have only had happen with points and condensers!) buy two and leave one in the glove box!

That sounds good, are they difficult to fit? (bare in mind I'm not great with electronics) Any recommendations for a particular kit?

[CityEPete]

Any of the Ebay ones are ok, I've used them all over the years, fitting is easy but you will the timing setting after but you might need that checking anyway as you say.

[Mini Manannán]

 

 

I had this a while back, had the timing adjusted and it sorted it, has slowly started to come back again now though so I think it needs adjusting again.

Get an electronic ignition kit, fit, time the ignition and forget it forever   If anyone says "yeah but what if it fails and dies without warning" (which I have only had happen with points and condensers!) buy two and leave one in the glove box!

That sounds good, are they difficult to fit? (bare in mind I'm not great with electronics) Any recommendations for a particular kit?

 

 

from the FAQs: http://www.theminifo...step/?p=2767772

[minicrystal13]

thanks everyone for your help im going to look at the cheaper options first see where I go from there, hopefully it isn't anything to do with the head.

 

cheers again Sam

[bob540]

 
from the FAQs: http://www.theminifo...step/?p=2767772

Thanks mate :) And sorry for hijacking.

[cal844]

If the engine tries to keep going after you have switched it off, try switching off slowly(from run to acc, then wait a second before switching to lock and pulling the key from the barrel)

If that doesnt solve it, tweak the ignition timing

Edited by cal844, 15 June 2015 - 08:28 PM.

[Dan]

  I'm sorry but I can't work out what it is you think that will do.  Running on occurs because there are hot spots in a cylinder and there is fuel in the carb float chamber.  Because the carb is a passive fuel delivery system, as long as the pistons are going up and down some fuel will flow from it until the level in the float chamber is too low.  If the cylinders are hot enough for some form of ignition it will fire and the pistons will keep moving.  Running on doesn't depend on the ignition system at all and even if it did, once it's off it's off.  Switching it off sequentially won't change anything.