2002 Mercury Villager Q&A
2002 Mercury Villager Question: Engine misfires when weather is humid.
Make sure the wires you purchased are high quality or even better yet - original equipment wires. I still think you may be experiencing some arcing from the wires. The key thought here is the moisture content in the air when the problem occurs. To confirm, get a spray bottle with water and while the engine runs, spray around the plug wires. See if the car stumbles. Beyond that, you could have an injector or harness issue. - DaveJHM