Merc 454 Big Block Problem
I wonder if anyone can shed some light on a problem I have with my 454.
The engine missfires when it is running under load when the rpm is between 2000 and 2200. Sometimes the missfire is dramatic enough to stop the engine dead. But yet when it is over or under there is no problem, I can't reproduce the problem out of gear.
I thought it was a valve stuck open but that would impact at any rev/speed and that is not the case. I have gone through each plug and tried running it without one pot on each and the problem remains
Any clues guys?