I have fitted new plugs and car ran ok, then misfire at high revs, now will not start and poor spark on external plug, fitted sec/hand dist/cap spark ok then fell away to a weak spark again, any ideas ???
Check all cables properly fitted/seated.
Possibly distributor cap dirty/corroded inside - check and clean. Similarly the rotor arm. Worst case the distributor cap is cracked get a new one (and rotor arm whilst you are about it) at Halfrauds.