no spark mystery!! SORTED

[Pifflebus]

Good evenin' folks! Here's one for you, I have a spark from the coil, nice and bright blue/white. However I have no spark at any spark plug despite brand new rotor arm, dizzy cap, condenser, points & HT leads, and fairly new, very shiny spark plugs. The van was running yesterday!!

Feeling a touch perplexed, anyone got any ideas?

Cheers,
Billy

[BOXY]

Check the spring loaded carbon contact in the top (inside) the cap is still there. They can snap off or stick and stop the wiggleys getting to the rotor arm.

[Pifflebus]

It is still there Boxy, but thank you!

I should also have said that the rotor arm is turning as it should, and the points are opening and closing

[BOXY]

If you're getting a spark out of the end of the coil lead then there's not much else that will stop the plugs sparking. The dizzie cap connects the lead to the rotor via the carbon contact. As the rotor arm turns it connects each lead in turn as the tip lines up with the inserts in the cap and lets the spark jump. Each insert is connected to the plug's HT lead and that lets the spark pop out at the plug.
If none of the plugs are firing either the arm or the carbon contact is the problem.

[Pifflebus]

Cheers Boxy, you are absolutely right, it is driving me crazy, the rotor arm and dizzy cap are brand new on today, because cleaning up the old ones didn't fix the problem ! I am really confused. Tomorrow i shall try putting a bolt or something in the end of the HT lead to test the spark without the spark plug. It is the last thing I can think of! I am supposed to be getting on a ferry on Wednesday and the old girl isn't even MOT'd..... looking bleak!

[BOXY]

Take a spark plug and one of the leads and switch it for the HT lead and let the plug sit against the engine block. If it sparks you've proved that lead and the plug are ok. Put the "proper" coil lead back in and the spark plug lead back where it should be. If you lose the spark the rotor arm or carbon contact have got to be the cause.

[Pifflebus]

Ok, thanks a lot boxy!



I shall let you know how it works out!

[Pifflebus]

Ok so...

From the coil:
with lead - spark
with lead + plug - no spark

From dizzy:
with lead - no spark
with lead + plug - no spark

So it seems I have 2 separate issues! It seems a bit bizarre to me that all the plugs should go at the same time. And then as you say there must be a problem with the rotor arm or carbon contact, but I have tried with the old and band new cap and arm, and get no spark either way!

[marlinowner]

Have you tried going back to the original ht leads?

[Pifflebus]

I have mate, thanks! Either way I get a spark from the coil (through proper coil lead or plug lead) but nothing with plug attached, and no spark from the dizzy regardless!

With the ignition on, I get a spark at the points when they open, and they are set to the correct gap. But any combination of old/new rotor arm or cap cannot produce a spark at the lead! And I can see that the carbon contact is making contact because there are black marks on the top of the rotor arm!

Is it just me or is witchcraft at play here?

[marlinowner]

Can I just clarify if this was originally a fault on the van, or the problem arose after changing parts on the ignition?

[Pifflebus]

SORTED IT

I knocked the choke cable cable off the coil while doing carb adjustments before the electrical problems. Electrical problems occurred because I put the cable on the wrong terminal on the coil.

Can't believe that! Just got to get her tuned up now!

Thanks for your input guys, turns out I am just an idiot!!

[marlinowner]

Nice one, its reassuring when it turns out that there's a logical explanation for problems which don't seem to make sense!

[ladybird]

[ghost123uk]

Glad you got it sorted Billy

But :-

I have a spark from the coil, nice and bright blue/white. However I have no spark at any spark plug.

And :-

SORTED IT. I knocked the choke cable cable off the coil while doing carb adjustments before the electrical problems.
Electrical problems occurred because I put the cable on the wrong terminal on the coil.

Is very odd because you did have a spark from the coils HT lead

Anyway, doesn't matter, all's well that ends well