holley power valve

Double check you dont have a burnt plug wire. Does it idle at all? Puke black smoke when at idle? Did it start this all of a sudden, or did it progessively get worse? If you think it's in question, for $7, just replace it. I'd probably just rebuild it (I like the AED kits..everything is reusable...) at the same time if it's older than 2-3 years. As they mentionned too, it may be a symptom, not the cause. Verify your timing chain hasnt jumped if the engine over 50K miles on it, verify the timing curve and it's parts in/on the distributor are working properly. (a timing tape for $3 will go a long way to checking this stuf with a std timing light)