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Missfire? Plugs and Leads

Posted: Tue Oct 18, 2011 10:12 pm
by Edweird
Hey up lads and lasses.

Firstly, I'm having another spluttering problem, but this is more intermittant, is worse in the damp and doesn't occur beyond what I reckon to be about 2000rpm. I think it's ignition related. Any ideas for diagnosis? I have a multimeter.

I get a staff discount at Halfords, along with trade discount on parts, so I can get a set of NGK plugs for £8.50. Is that a reasonable price? I get the same discount on leads, which come to about £18 for all 5 leads.

They also do these special Bosch 'super 4' plugs. Plugs with 4 electrodes. The automotive fitter, Paul, at work rates them pretty well and he's a trustworthy chap. I can see them being a pain to gap but otherwise okay, but they cost an extra £4 on top of the NGK's after discount. Are they worth it?

Cheers, Ed.

Re: Missfire? Plugs and Leads

Posted: Tue Oct 18, 2011 10:16 pm
by Henry
probably not. Get some spray that you put on to "aid starting in damp conditions" Carnt see such modern plugs doing much to the 1L sj engine!

Mine cuts out in any type of water or rain/splash up. Plan is to get the "fine mist" setting on the hose pipe at night, on tick over spray over engine bay and look for arcs!

Re: Missfire? Plugs and Leads

Posted: Tue Oct 18, 2011 11:55 pm
by Christoff
For what it's worth get a new set of plugs and leads on. Might as well have a new dizzy and rotor arm too. Their cheap parts and will rule out a lot of potential problems. Just my opinion anyway

Pointless chasing around after other running faults of your unsure about the condition of the basic ignition components. After that you can start looking at carb settings, compression testing etc

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 8:52 am
by ScottieJ
Is your hot air feed from the exhaust manifold fitted? If so have you opened up hot air intake on the airbox? Could be carb freeze if not now that it is getting cold.

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 9:14 am
by twiss
I've tried the super 4 plugs and the Y split plugs. I think there is a small difference between them and regular plugs but I cant really tell the difference between the two

I normally find that sputtering ends up being water in my distributor, or knackered leads

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 9:35 am
by dan_2k_uk
on the subject of this I have just tried something I have been meaning to do for a while.

just did a test using an 11kv glue filled shrink terminal boot at work to see if it would shrink down to the size of a distributor and it does.

going to use it to seal over my distributor cap/housing joint and got some of the same stuff but smaller to seal the HT leads to the plugs and the cap.

Should be totally water proof.

just need to make something up to clamp the cap down so I can loose the old cap clips

will let you all know how it goes

Dan :thumbup:

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 6:25 pm
by Edweird
Thanks for the rapid responses folks.
Henry wrote:Get some spray that you put on to "aid starting in damp conditions". Can't see such modern plugs doing much to the 1L sj engine!

Mine cuts out in any type of water or rain/splash up. Plan is to get the "fine mist" setting on the hose pipe at night, on tick over spray over engine bay and look for arcs!
My step-dad suggested that spray stuff. Where's likely to have some, 'cause I'll try that before buying plugs and leads if it's cheap? I had a feeling that would be the case with the fancy plugs too.
Christoff wrote:For what it's worth get a new set of plugs and leads on. Might as well have a new dizzy and rotor arm too. Their cheap parts and will rule out a lot of potential problems.
It had a new dizzy cap, rotor, condenser and points not too long ago, but I'll keep that in mind.
ScottieJ wrote:Is your hot air feed from the exhaust manifold fitted? If so have you opened up hot air intake on the airbox?
Yep, already did that 'cause the weather's getting colder.
twiss wrote:I've tried the super 4 plugs and the Y split plugs. I think there is a small difference between them and regular plugs but I cant really tell the difference between the two

I normally find that sputtering ends up being water in my distributor, or knackered leads
Similar to what Henry said then. They're better, but not by a lot. The leads ARE the originals so it could be that.
dan_2k_uk wrote:on the subject of this I have just tried something I have been meaning to do for a while.

just did a test using an 11kv glue filled shrink terminal boot at work to see if it would shrink down to the size of a distributor and it does.

going to use it to seal over my distributor cap/housing joint and got some of the same stuff but smaller to seal the HT leads to the plugs and the cap.

Should be totally water proof.

just need to make something up to clamp the cap down so I can loose the old cap clips

will let you all know how it goes

Dan :thumbup:
What's wrong with a rubber glove and cable ties?

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 7:16 pm
by twiss
Mine was sputtering intermittently, then I went through a big puddle and it cut out...

Big puddle =

Image

;)

Went to take off the main lead from the coil and the end of it came off :lol:

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 7:55 pm
by Henry
If they are the orig leads GET EM CHANGED! :lol:

Re: Missfire? Plugs and Leads

Posted: Wed Oct 19, 2011 10:54 pm
by ScottieJ
I had to ask Ed :lol: its an easy thing to forget :lol:

Have you checked the gap on the points? Also sometimes cheap condensors don't last that long, can you remember what brand you got?

Checked the coil resistance?

And yeah as Henry said its always worth fitting new leads if you haven't already.