I am also wondering about the coil. I dont think they are terribly expensive so probably worth throwing a new one on.
Any suggestions for brand and model?

 

Good ~ air leaks can be a pain.

I've suffered this my whole career. People ask their mechanics about lubrication. Mechanics know FA about lubrication. It's not part of their training & they are not willing to learn. As an industry we've tried hard. They just perpetuate old wives tales. In fairness the East Asians want to learn. Thailand & East of.

 

Coils have a life of approx 100K miles. Very approx. and dependent on abuse. e.g leaving the ignition on for extended periods without the engine running.

I'm sure you can find a Lucas Sports Coil in Aus. or Bosch make great coils.

I'm running a Pertronix Ignitor pointless ignition with a debranded Pertronix satin chrome Flamethrower coil. See thread in my signature.

 

As a very broad rule, if you have a points ignition you want a coil primary resistance of around 3 ohms and electronic ignition around 0.5 ohms. Pertronix may be different, I don't know the spec for that.

 

The Flame Thrower 40,000V coils have internal resistance rated at 1.5 or 3.0 ohms. I am running 3 ohms & no ballast resistor as recommended. Positive earth. Amazingly they still make for Lucas 22D6 +ve earth.

They also produce 0.32 & 0.6 ohm 45,000V coils. All coils are clearly marked which systems they are suitable for.

 

While talking about ignition systems one of the critical items is the condenser normally buried in the distributor. Most people don't realise that it is a critical part of the spark generation system. It is not there to "protect the points". The condenser is actually part of a system called a series oscillator or sometimes called a "bell ring" circuit. The primary side of the ignition coil discharges into the condenser which in turn again discharges back into the primary coil and the cycle repeats but steadily decaying.

All that produces an oscillating voltage into the secondary winding of the coil which produces the spark. If viewed on an oscilloscope it is not a single spark but actually a series of sparks. Condensers do decay over time and should be replaced every time the distributor points are replaced. I suggest that if wouldbeowner is replacing the coil then a new set of points and new condenser should be on the shopping list.

I actually had a case today where a Daimler 250 was not behaving although it had new points, coil, and condenser fitted. I finally diagnosed the new condenser was faulty and another one was fitted which cured the problem.

Bill Mac
MK1
MK2
S3XJ6
X400

 

Condensers do indeed dry out & get tired. I think WBO did points & condenser when he got the car. But this is sound advice and should be a priority if it has not been done recently!

 

Hello all. No I have never done the points or condenser so thanks for pointing it out as a possible iss. Would a faulty condenser fit with the issue I am having ie the misfiring gardually decreases as the engine gets warmer?
TIA

 

Not particularly but possibly aggravating.

Symptoms of a failing condenser are usually

1) Hard starting
2) Rough running
3) Misfiring.