My young lad has a 1999 Explorer 4.0l sohc. He recently had a couple of wires come off the coil pack , I don't know how, but he plugged them in as best he could. Then it started running terrible and the starter failed. We changed the starter, it would crank but not start. We changed the plugs, this is when he told me about the plug wires. Well sure enough the firing order was wrong , numbetr 3 and 6 were crossed. We fixed this up and got it to start but it doesn't run well. Does anyone have a guess as to how much damage could result from the mixed up wires? Thanks

 

My guess as far as damage , would be little . Other than a fouled plug that is . Unless he drove fore an extended period of time ... I have seen people drive for hundreds of miles with a misfire with no damage . I have also seen cats melted in 20 miles with a bad misfire .

 

My guess would be that if the plug wires popped off, they are probably not a real high quality set of wires. After playing with the wires to get them reconnected, disconnected to replace plugs, then re-arranged, one or more of the inexpensive wires probably broke internally at at one of the crimps. I'd suggest starting over with a new set of spark plug wires, being very sure to get the wires connected correctly. Keep in mind that Ford numbers their cylinders differently than GM and Chrysler. On your Explorer, assuming it is for the US market, cylinder number 1 is the front (near the radiator) cylinder on the passenger side of the engine. The next cylinder on that bank is 2, and the cylinder near the firewall is 4. Cylinder 4 is back at the belt side of the engine on the driver's side cylinder bank. The middle cylinder is 5, and near the firewall is cylinder 6.

-Rod

 

I would agree, if the wires popped off, then either the clips are broken, the wires are cheap, or the coil pack is cheap. That is likely part of the issue.