27 replies to this topic

[Kernal H]

Today I found the cause of misfiring. Poor HT leads that were earthing together and on body work.

Anyhow, in the dark you can also see all the spark plugs lighting up, just around the base of the white bit. Nice and blue (showing a good mix I beleive), anyway are they ment to be this colour in the dark, and will it do any damage to the engine/performance?

Need to know what else I need to buy

Cheers!

[carl68]

Today I found the cause of misfiring. Poor HT leads that were earthing together and on body work.

Anyhow, in the dark you can also see all the spark plugs lighting up, just around the base of the white bit. Nice and blue (showing a good mix I beleive), anyway are they ment to be this colour in the dark, and will it do any damage to the engine/performance?

Need to know what else I need to buy

Cheers!

Sounds like you need a new set of plugs. You are seeing arcing which is making the spark at the electrodes weaker. The blueness of the spark you are seeing is not showing a good mixture as its not igniting any fuel, its just an arcing spark.

[icklemini]

you need to refresh your ignition system - a new set of quality spark plug leads and plugs should improve things no end..

ttfn,
Dave

[Kernal H]

Cheers, my dad said they shouldn't do it... but I wanted a second opinion! I'll add it to my list of parts that I've already replaced once and need replacing again after 2 months of doing nothing

Icklemini - I've already replaced all the ignition once about two months ago due to poor spark! But at least now I have a rough idea of whats happening with it. All thanks to early dusk!

Edited by Kernal H, 11 December 2007 - 08:43 PM.

[insamoufonyx]

its worth getting proformance leads and plugs, last longer and power enhancing

[Kernal H]

Performance it is! I'll see how much more expensive they are first tho... I don't want to spend loads. I still have an MoT to pay for!

[ginigwunkle]

my ht leads were 45. ther magnecore red race leads,

id also say ngk bp6es plugs too, only about a tenner,

do you have electroinc ignition? if so then bpR6es plugs.

check points and condensor too!

[mini93]

older leads, when they get covered in cr*p and dirt and genraly get old the coating cracks allowing HT voltage out between these to the earth point, basicly going the easy way rather than jumping the gap across the electrode on the plug

my rally car was misfiering on 1 and 4 cylinder the cyramic white material had crack, i hadnt touched them but just happened when i came to start one day, this gave weak/no spark

a good set of sylicone leads should solve it, sylicone leads are less likly to crack and damage compaired to the old material...make sure you have the right plug with correct gap set too

[Big_Adam]

Riight, you paid £45 for leads.

For £20 I can get leads, plugs, point, cap and a rotor arm for the dizzy.

[Jammy]

As said above, for anything on the road, or even partial track use, a half decent 8mm set (Halfords, Bosch, the blue Silicon stuff from MS) and you'll be fine, you really don't need to spend loads of money on HT leads. In front of the engine just doesn't get hot enough for the HT leads to degrade much at all.

[Kernal H]

OK this is really starting to annoy me.

I've just bought BRAND NEW HT leads and BRAND NEW spark plugs. The leads are better but still earthing out on each other. It's not back-firering into the carb anymore, but mis firering into the exhaust. When I replaced the plugs, it looks like 2 cylinders are running lean and 2 are rich. Sadly I couldn't tell which since I only looked at the plugs inside (where it was light).

Just to check, the lead order for a lucas dizzy is 1-3-4-2 anti-clockwise from 2 O'Clock. And I can't remember the point's gap (which wouldn't cause misfirering but I'll check still). Plugs should be set at 25 thou of an inch? Mine came factory set, but I'll check these too.

The blue spark plug thing is still there, but less noticable. And all the arcing that's occuring is only seen in the pitch black, it would be good to see if any of you running NGK plugs can see a small blue ring around the spark plugs in the dark.... because it really is only a dim light

[mini93]

distributor cap in good working order? and the rotor arm

also what inlet manifold is being used, a poorly distubuting manifold can give incorrect mixture leading to differing spark characteristics
blue spark plug tho...no idea lol

[Kernal H]

I've replaced the dizzy cap twice, this one is clean and pretty much new, the rotor arm has also been replaced and looks in good order. Currently I've got a KnN air filter with standard exhaust and manifold, all without any air leaks. I'm gonna go over everything with again when it's light (which'll be friday earliest ).

I'm just sooo confused. If anyone has a trailor they can lend me it would be great! Then I can get someone who know's what they're doing to look at it!

[mini93]

well the standard manifolds arent going to be a problem and as the air filter is past the manifold its not going to be the problem

what colour are the new plugs after being run? should be slighly browned/tan with very light deposits on

do you have access or anyone you know have acces to a compiression tester?

[Kernal H]

I'm not sure, I'll ask the guy with the series 1 has a compression tester. He has most things! I'm not able to give the car a proper run tho, it's off the road and needs an MoT. I'll run it up and down my [private] road and check after that. I suspect that due to the shorting HT leads two cylinders arn't firering properley and thus they have a very rich mixture, whilst the other two have been running lean due to me leaning out the mixture trying to solve problems.

I think I need to spend some quality time in the light looking at EVERYTHING and trying to narrow down what might be causing it. I guess blue plugs could be normal, but no one's ever looked at them whilst in complete darkness and thus never seen it happening. Very odd tho.

Edit: thanks for the help mini93

Edited by Kernal H, 12 December 2007 - 08:24 PM.