It is suggested that ignition coil be replaced when replacing this control unit. Installation Instructions By design, Perma-Tune ignitions make very little heat of their own. Wiring problems external of the unit will cause your Perma-Tune to get hotter to the touch than the other components under the hood. If this is the case we recommend you read the diagnostic instructions. The Model 911 increases spark energy three times that of the stock ignition system. This is why spark plugs will never foul again, can be set to .065" spark plug gap and will actually recover from fuel contamination. The Perma-Tune system uses the points only as a sensor so they will generally last the life of the engine. Dwell is not a factor simply set the points to stock gap specifications and then adjust the engine timing using a timing light. The Model 911 Perma-Tune is designed to replace the stock ignition box and will bolt up and plug in to the same location as the stock system. If the connector on the box does not fit the car harness connector, you have the wrong box. If you have a turbo charged car, be certain that the speed relay has not caused the previous ignition box to fail before plugging in the new box. If you are installing a 911SC engine in a 911 body, use the model 911EX Engine Exchange kit. If you need a harness to install this ignition system, exchange it for a Model 911E Perma-Tune. Use the Plasma Drive Perma-Tune for late model Porsche engine management systems, hall effect distributors or after-market engine management computers. Use the Model MP Perma-Tune on magnetic pulse type distributors like the Porsche 917 or any other magnetic sensor. For Perma-Tune products,customer MUST call Perma-Tune directly @ 631-909-1011 PRIOR to claiming any unit as warranty. Or contact Perma-Tune @ for further information.