Spark Plugs

kiwi · Post by **kiwi** » Fri Aug 03, 2007 8:30 am

Thought I would share this little experiance with you.

Ever since I got my BX it has been a pig starting from cold especially on the colder mornings, being winter here thats nearly everyday. Well since I got the spare parts car I started to think how unfair a car that was about to be dismantled started first time and mine just would be pig headed

Decided to change the spark plugs and after a checking with our local mechanic we came to the conclussion that the information in the parts books he had was incorrect. After consulting the haynes manual and BX handbook we finally figured out the ones he could get were Champions.

Sweet so out comes the old ones! Question to me is they looked fairly new probably when the last owner who was a Citroen Mechanic replaced them.

Here is what I took out Eyquem RFC58LZK.

Now they are not in any of the parts books I have so what car do they fit?

Ever way the BX started first time from cold with a little blip of the accelerator. Seems I cured one problem!
But wondering why the heck he put in a French made spark plug of the wrong type?

jeremy · Post by **jeremy** » Fri Aug 03, 2007 9:06 am

I think he fitted the correct ones!

http://www.eyquem.com/

kiwi · Post by **kiwi** » Fri Aug 03, 2007 9:52 am

The plot thickens

Ok so now I wait and see if the little monster goes back to its old habit after a few weeks on runningon these new ones.

The plugs I took out were spotlesly clean with no obvious signs of electrical tracking or any of the other nasties. Better get a photo up I guess, next stop fuel filter and oil change the air filter is clean.

jeremy · Post by **jeremy** » Fri Aug 03, 2007 12:42 pm

Providing the plugs were the correct shape (ie reach etc) I wouldn't have expected the grade to have made any difference that wasn't apparent.

What I mean is that too hard a plug (cold running) might be prone to fouling especially on oil burning engines and too soft might lead to detonation (pinking) at high speeds which could destroy the engine. Most engines will start on a clean plug irrespective of its grade.

What is the gap? The reason I ask is that my long departed Renault 21 was extremely sensitive to gap - and if they got too large it would barely run. I have memories of a horrible run in the thing and removing the plugs at my destination and closing the gaps up a bit whereupon it ran perfectly for the return journey.

kiwi · Post by **kiwi** » Fri Aug 03, 2007 10:05 pm

What is the gap?

Now this I am ashamed to say I have not been able to check, to make sure they have not been banged and closed up to much. I had a spark plug gap checker tool back in blighty but this seems to have gone walk abouts like a couple of other things when my parents packed up and headed this way.
I am hoping my Father has it hidden in his tool kit but I know we will argue look and hard over the ownership

So far I have not found one in any of the motoring shops over here, I find this odd but then again considering my dad asked for a building tool commonly available in the UK and was told they could not sell it to him unless he had a certain trade certificate. Nothing surprises me

stuart_hedges · Post by **stuart_hedges** » Fri Aug 03, 2007 10:39 pm

Interesting.

Plug gaps is one of those things I used to check but found it never made the slightest difference to the running of the car so have stopped bothering to do it!

mountainmanUK · Post by **mountainmanUK** » Fri Aug 03, 2007 10:50 pm

I think it used to be more important with older vehicles (60s-70s etc) than more modern types.
I remember religiously checking valve clearances, plug gaps, points (anyone remember them?), etc. every week!

The only problems I ever had with plug gapping, was if the gap was too wide. You could generally get away with having a smaller gap than the official spec, if your engine wasn't particularly oily. I eventually developed an 'eye' for setting a correct gap for my cars, which seemed to work well.
I used to set the top electrode (with the bend) so it was sitting at 90 degrees to the centre electrode. This equated to a gap of 0.8-1.0 mm.
It pays to take a little care when refitting plugs, as if you drop them roughly into the 'hollow' before screwing them in, the top electrode can bend easily, thus closing the gap.
An old tip was to have a 6-9" length of rubber hosepipe, and push the outer end of the plug into this to lower into hole and beging screwing in.

AndersDK · Post by **AndersDK** » Fri Aug 03, 2007 11:39 pm

This Eyquem plug should be set to 1.0mm gap for the BX.

Later cars have more than adequate HT power to overcome larger plug gaps. Was only an issue on earlier cars.