Abrupt Misfires

[BeefKeith]

I have a 2003 Ranger 4.0 4x4 with the 5 speed in it. I suddenly had misfires on the way to work, and a scan showed misfires in 4,5 and 1. Put a new coil pack in it and new spark plugs, another scan then showed misfires on 4 and 5, with lean banks 1+2. Idles super rough, and I hear a clicking noise coming from the engine compartment. There was a whirring sound in the days prior until the truck got up to speed, and there's been misfiring issues in the last month, but those were chalked up to a fuel filter and an unplugged vacuum line in the passenger side. Any help would be appreciated.

 

[franklin2]

Take something flammable like brake cleaner or a unlit propane torch, and play it around the intake manifold with the engine running. If you are using brake cleaner, spray it around with the engine idling. You are checking for air leaks. If you find one, the engine will suddenly suck in the propane or the brake cleaner, and run differently.