Hello, on my 96 XJS 4.0 I6 I have been experiencing a miss in the engine. At idle with the car in neutral it runs smooth, however if I shift the car into drive I feel a random misfire. It seems to occur only under a load. I can also feel the misfire when in neutral I kick the accelerator down. Plugs are just replaced. Could I have a failing coil pack? I have no codes on the dash.

Any thoughts?

Thanks,
Steve

 

Coil pack problems are not unusual as you know. As guesses go, it wouldn't be a bad place to start. Lacking a trouble code to identify which cylinder is misfiring you could buy one coil and just try it on all 6 cylinders. If one of the coils is bad you'll eventually find it :-)

Cheers
DD

 

Thanks Doug.

I was thinking I may give this a try. Looks like I can buy a single coil pack as well. Is there any visual tell-tales for a bad coil pack? Burnt or cracked epoxy resin maybe?