Spark plugs (yes, i've searched)
Turbo Mini Forums

Hi folks, after some advice on what plugs to run for my 998. It's a 99HE20 engine (high compression) currently running with RN9YC plugs.

I've now moved over to megajolt ignition, but have also had the problem of it pre-ingiting a bit after a long drive when you switch off the engine. These plugs have been on the car since i've had it and the problem has always been there, even after fitting MJLJ.

So my guess is I need a cooler plug? What can you reccomend for me? Any help is greatly appreciated.

Cheers.

Is this a turbo engine?

Do you mean the engine is running on after the ignition is switched off?

I don't think a cooler plug is going to help you here. RN9YC should be fine for your application.

Its non turbo. Perhaps it is run on, but it's not smooth, very jurky, I thought that was the difference?

What else do you think the problem would be if the plugs are the right temperature? It will only do this after a long run also, if you let the car get to temperature after starting it, and switch it off, it will not run on.

the plugs fine on this engine

causes are low grade 95 ron fuel

ignition timing too advanced for low grad fuel drop it back 3 degrees or so

keep us informed

Edit - nevermind, i've answered my own question by looking at sparkplugs.co.uk . Great website!

Edited by Carl S on 6th Aug, 2009.

Ok, bought a set of BPR6ES plugs from my local motorfactor as i fancied trying NGK instead.

Found a possible reason for the run on as well, one of the plugs previously fitted was two grades hotter than the rest!! So whoever serviced it before me was obviously stevie wonder or very backwards.

Hopefully it's 'case closed' now.