Technical backfire under load

You're right cams can behave differently when warmed up if a lobe is going flat...but since I'm cheap I check easy, cheap stuff first. I've found plug wires a more common sore spot. The fact any of this stuff lasts as long as it does constantly amazes me.

 

If not already said...I have seen coils act up and even shut down when hot. Seem it more with Ford's than anything else. But seen it with Chevys and Mopars too. Gene.

 

Thanks for letting us all know what it was. Mystery solved! Good job!

 

You're welcome , I know you know I was pulling your chain about the radiator cap ..