Rough Idle and Stumble
Thread Starter
Instructor
Joined: Apr 2012
Posts: 168
Likes: 26
From: San Lorenzo CA
Rough Idle and Stumble
My 2004 coupe recently developed a rough idle and severe stumble at about 1500 rpm under load. Upon checking for a loose plug wire, I discovered two wires which were severely burned. Hesse wires were aftermarket wires from Summit Racing and has only about 20,000 miles on them. I replaced them with A/C Delco 9748MM red wires. Rough idle and stumble are gone and all is right with the world now. These OEM wires were about half the cost of the Summit wire and fit perfectly. 
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
My 2004 coupe recently developed a rough idle and severe stumble at about 1500 rpm under load. Upon checking for a loose plug wire, I discovered two wires which were severely burned. Hesse wires were aftermarket wires from Summit Racing and has only about 20,000 miles on them. I replaced them with A/C Delco 9748MM red wires. Rough idle and stumble are gone and all is right with the world now. These OEM wires were about half the cost of the Summit wire and fit perfectly.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If the wires are physically contacting the header/manifold, eventually it will destroy the wire. If you do have contact, get some COOL SOX and install it on the boots/wires.
Bill
Bill
