2004 Chevy Silverado rough idle after new plugs&wires

[Dawn Reynolds]

Recently replaced plugs and wires in 2004 Chevy Silverado Z71. It now idles very rough almost to the point of stalling and misfiring. I found a forum somewhere that mentioned wrong plugs but now can't find it to show the hubby. Any help is appreciated! Love these forums!

[Sharpz]

It could be the wrong plug, or just not gapped properly. It could also be faulty wires.  If he kept his old plugs and wires, replace one plug at a time with one wire at a time, starting with the number 1 cylinder and making sure the wires are securely connected. 

[txab]

Plug gap is .040. Used to be .060 in previous years. Some places still pull up the old plug number. Make sure you've got the right plug gapped at .040 from the box.

 

You can use Iridium (OE), or use Double Platinum. Suggest AC Delco, NGK, or even Denso. All are good plugs

 

Also make sure plug wire is securely pressed onto the plug

Edited April 15, 2021 by txab