misfire help

[bobfather]

I've been suffering misfiring for the last few days, 4ltr serp. Very lumpy when first started from cold especially when damp. Once warm the misfire is only present when at low revs and low power, i.e. when in slow traffic. There is evidence that it may be more prevalent when travelling around a righthand bend. There's no hint of it when the car is at speed.

I'm suspecting HT lead breakdown or some other ignition related fault.

Any help would be greatly appreciated

Edited by bobfather on Monday 3rd August 17:40

[bobfather]

Really? The symptoms appear to be ignition related

[bobfather]

Plugs, dizzy cap, roter and leads were replaced last service 2k miles ago. I've popped the old leads back on, just waiting for dry roads to test it now

[bobfather]

Thanks ChimpOnGas, I was running without extenders when this fault started. The leads were protected with heat resistant socks and the cables pulled to maximise distance from the headers. There was no sign of heat damage to the cables but I was conscious of the fact that some of the leads were stretched due to having no extenders. This caused the leads to have firm contact on metal parts of the engine and the potencial for the cables to separate from their caps. This is why I decided to eliminate lead faults first by refitting my old leads complete with extenders.

After fitting the engine ran okay but I still need to drive it to see if the misfire is still present

[bobfather]

Thanks ChimpOnGas, I was running without extenders when this fault started. The leads were protected with heat resistant socks and the cables pulled to maximise distance from the headers. There was no sign of heat damage to the cables but I was conscious of the fact that some of the leads were stretched due to having no extenders. This caused the leads to have firm contact on metal parts of the engine and the potencial for the cables to separate from their caps. This is why I decided to eliminate lead faults first by refitting my old leads complete with extenders.

After fitting the engine ran okay but I still need to drive it to see if the misfire is still present