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Furry spark plug

Posted: Wed Apr 04, 2018 12:47 pm
by Jim
Hi guys, I've recently been having a weird popping sensation around 2k revs and above but stops after about 3k. I've pulled the plugs and they all seem okay but the 3rd cylinder from front. The plug is 'furry' on one of the sides and did smell quite strongly of fuel and oil when I first pulled it, more so than the others. I've attached photos to show what I'm talking about. Could it be that this spark plug is knackered and isn't firing properly causing the strong smell of oil and fuel or could it be something else. I would just run the car with new spark plugs and see if the problem has gone away but didn't want to mess up a perfectly good spark plug if someone knows that it may be something else.

Any help would be greatly appreciated.

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Re: Furry spark plug

Posted: Wed Apr 04, 2018 2:30 pm
by Paul G
Did you get my email?

P.

Re: Furry spark plug

Posted: Wed Apr 04, 2018 8:02 pm
by Jim
Paul G wrote:Did you get my email?

P.
Hi Paul, haven't recieved anything no, sorry.

Re: Furry spark plug

Posted: Wed Apr 04, 2018 8:41 pm
by Paul G
Email re sent. It had stuck in my Drafts box rather than sending.

P.

Re: Furry spark plug

Posted: Sun Apr 08, 2018 6:46 pm
by Jim
Paul G wrote:Email re sent. It had stuck in my Drafts box rather than sending.

P.
All received. Many thanks Paul.

Re: Furry spark plug

Posted: Thu Apr 12, 2018 4:06 pm
by nigecapri
Off with the distributor cap & check the copper/alloy segment for #3 lead is in good condition - scraping clean if claggy should help but new cap is best, also check the shaft for sideways wobbles - badly worn can give a poor spark for one plug. If no improvement then just fit one new plug in #3 and test it for improvement. If no change then get a replacement HT lead for #3 & test.

Re: Furry spark plug

Posted: Thu Apr 12, 2018 5:16 pm
by Paul G
nigecapri wrote:Off with the distributor cap & check the copper/alloy segment for #3 lead is in good condition - scraping clean if claggy should help but new cap is best, also check the shaft for sideways wobbles - badly worn can give a poor spark for one plug. If no improvement then just fit one new plug in #3 and test it for improvement. If no change then get a replacement HT lead for #3 & test.
I stripped and rebuilt the head for James middle of last year due to other problems but it was rebuilt with top hat valve stem oil seals etc. The distributor is fitted with an aldon igniter type electronic ignition and the shaft is OK (dead steady pointers with strobe on it) and the cap and leads were new.

James has fitted a new set of plugs which have cured the running issues but when the head was off we noticed that the bore on no3 was slightly scored which is where the oil contamination and burning must be coming from. Compression was still OK Just for now he's going to run the car as is whilst it runs OK with no smoke coming out or heavy breathing, just keeping an eye on the plugs, but long term a rebore is on the cards.