7 replies to this topic

[Cazy82]

Ok so a few weeks ago car went lumpy and discovered running on 3 cylinders. Spark plug 3 failed. It was black and sooty. The rest were perfectly fine.

Changed the spark plug and boom, off he goes. Roll on to 3 days ago. Same thing again, same cylinder. Yet another black sooty plug!

Any ideas? I’m going to change the leads and full set of plugs but I’m a bit concerned this is more than a lead and plug problem. Starting to suspect engine issue and if that’s the case I’m going to be gutted!

Any help welcome.

[gazza82]

Try swapping leads 2 & 3 on dizzy to plugs. Then if no 2 fouls, it's the lead.

Edited by gazza82, 12 June 2019 - 06:12 PM.

[Cazy82]

It blows the actual plug though. I swapped the plug initially from 3 to 2 and 2 wouldn’t work! This is what is confusing me. Leads all work fine when. I replaced the plug initially but it’s the same one gone again. Tried swapping plugs again and the plug is blown! Does that make sense? Lol

[Cazy82]

Will still try new leads initially. Starting to ponder head gasket

[cal844]

How old is the fuel? Does it do it when it's cold or hot?

[ukcooper]

could be the piston hitting the plug if you don't like the lead opinion  or fuel one???????????????????oh the there the valve one or block cracked ??????????????

[Cazy82]

Fuel is fresh! Serviced regularly. Both times it has been fine when put into garage. When you start it you can notice it running lumpy right away

Edited by Cazy82, 12 June 2019 - 07:44 PM.

[richmondclassicsnorthwales]

Knackered distributor cap is also possible