Slight Misfire

[stagerooney]

I have a slight, hesitant, misfire when the engine is hot and under load. Replaced dizzy cap, plug leads, rotor arm and coil (ballasted), none of which have made any difference. No better, no worse! Should I try points and condenser next. (Standard twin points ignition). I fitted a Stag Weber conversion that worked fine up until the misfire started so cannot believe that is the problem. Engine starts well and ticks over smoothly. Possible fuel pump problem? Fitted with pressure regulator/ filter at 2.5psi. Any thoughts and ideas??

[Alacrity]

Personally I would always ditch the points & condenser setup. Quality points & condensers are difficult to find these day. A modern 'electronic points' setup is much better, I rate Pertronix as the best out there but there are cheaper options on the market. One problem I had with my distributor, giving symptoms like yours was a failure of the little flat copper earthing wire between the two moving halves of the distributor base plate, fitted a new one from the distributor doctor & it was sorted.

Good luck

Geoff

[stagerooney]

Thanks for the advice. I prefer to keep the points set up to be honest. I have just obtained NOS original Unipart points and condenser so will fit these next ,noting the copper earthing wire you kindly mention.
Opinions and experiences with electronic set ups seem to vary, good and bad!

[RobinLegin]

Based on the experience on my Alvis, I would change the condenser. Hesitation sorted.

[richardthestag]

speak to Distributordoctor.com about points and condenser. I am with you on retaining points, but setting up the stag distributor twin points is a faff, hence why so many swap out to luminition, newtronic/piranha, and more recently Pertronix.

Years ago I spent ages chasing down a misfire from idle, turned out to be a loose low tension wire to one set of points. Nipped the nut up and the issue was resolved. However the points quickly failed due to rubbish condenser.

Check plug leads are firmly and fully attached at each end, you may need to slip the insulated cap back up the lead slightly to get the contacts to click on properly.

The parts supplied in green boxes from many stag specialists and especially so if bought from an unknown seller on an online auction site may be more effective as a fishing weight. I have certainly knocked a few into next week using my old tennis racquet out of frustration

Same goes for distributor cap and wide tail rotor.