The OEM S54 Solenoid Coil pack is known for failure due to the solder joints inside breaking as a result of the vibration from the engine, among other failures.

These rebuilt coil packs by Beisan feature a number of improvements.

Information and replacement procedure can be seen here.

Price is £500, £300 of which is refunded upon receipt of your original coil pack. Installation requires part BS024, available seperately. When returning your core unit, include your name and order number – NO DETAILS, NO REFUND.