Distributor issues

[devilhenge]

So I've been working on getting a Vauxhall Nova started for a bit now, and the issue seems to be with the distributor, as there is a strong spark from the coil when put near the engine block, but all the leads coming from the distributor only produce a weak spark intermittently. I have checked the points within the distributor, and they produce a small spark (compared to the spark from the coil), so I think they are fine. If so, what other issues could there be, and how would I go about troubleshooting them? (Just one thing, when I was trying to get the distributor working before, I tried to clean the rotor arms contacts with a piece of sandpaper. After reading up a bit on this, i now realise it was a stupid thing to do, but would the damage be enough to top the engine from firing?)

[DrDeAtH]

Points? Condenser could be buggered
New cap and rotor arm would be a good idea.
Clean and gap the plugs.
Check the static timing.
Check the condition of the HT leads, replace if needs be.

[Steve H]

Big spark out of coil, small spark out of distributor cap?

If you are describing accurately then the spark is finding an earth in the cap or more likely shorting through the rotor. Change them.

[paintman]

^^^^Defective or pattern part rotor arms are a common problem. As can be the dizzy cap.
Also get someone to try starting it in the dark whilst you watch the dizzy.
You don't want to be seeing a sparkly display.