Hi All,
 
My daily driver is my completely factory standard 1979 1600 Escort panel van.
I drive it sedately mainly through residential streets at 50 to 60km/h, approximately 24km each day, 6 days per week.
Over the past 2 to 3 years I have been finding that I need to clean an opaque (clearish white) coloured glazing off the spark plugs every few months. If I don't, eventually the car just won't start.
All the spark plugs are bone dry with absolutely no trace of oil or fuel.
I use 91 octane unleaded fuel with no additives.
I blamed the fuel so have tried alternative petrol stations, choosing to buy only from one petrol station for several months at a time to make comparisons.
The glazing is a very thin hard coating bonded to the electrode which the spark can't penetrate.
A small file is needed to remove the glazing.
I have owned the car since early 1986 and have driven it almost every day since then.
In past years the spark plugs would just be slightly wet with fuel residue.
About 3 years ago I did re-jet the carby slightly leaner than standard.
 
Is any one else have similar issues?
 
Thanks,

Inspecting your spark plugs can give you a good indicator on how your engine is running. If I remember correctly your description sounds like your air/fuel ratio is running too lean. 

As above white is too lean. Black and oily is too rich.
 

Peter, thats odd. I run a couple of charades on bp 91 and go a couple of services (30k+) before changing plugs. The charades are efi and from the plug colour (white) run really lean so i dont think thats yor issue. Maybe your coil has lost some punch or the plugs arent running hot enough to clean.

PeterM
Over the past 2 to 3 years I have been finding that I need to clean an opaque (clearish white) coloured glazing off
the spark plugs every few months. If I don't, eventually the car just won't start.
......
About 3 years ago I did re-jet the carby slightly leaner than standard.

evobda2
... white is too lean...
 

Coincidence? Its probably running hotter (because its leaner) and possibly overheating the plug. Either change jets back or possibly change plug one heat range colder. See if that improves it, if you go too cold on the plugs they'll start fouling.
 
http://ngksparkplugs.com/...plugs/faqs/faqread.asp

Found the problem with this.....
I replaced the 400 year old sparking plugs.
Starts every time, and goes like a rocket ship!
Happy boy.