New Plugs New Bugs
Greetings,
This is my first post but I have gained a wealth of information by searching here many times before--thanks to all for your generous sharing of invaluable contributions.
Here's the problem: I have a 1997 with a 4.0L which was running fine but I decided to change the wires and plugs as they had not been changed in 70000 miles. I changed the plugs, first with Autolite platinums then with Champions same type as the old plugs. Gapped .035. With new plugs, the Jeep idles and runs rough--seems like a CPM issue. Old plugs, runs fine. I didn't replace the cap or rotor. Would a hotter spark from the new plugs cause more efficent firing thus causing the CPM to regulate differently? Should I replace cap and rotor also? Thanks in advance for any help given!
This is my first post but I have gained a wealth of information by searching here many times before--thanks to all for your generous sharing of invaluable contributions.
Here's the problem: I have a 1997 with a 4.0L which was running fine but I decided to change the wires and plugs as they had not been changed in 70000 miles. I changed the plugs, first with Autolite platinums then with Champions same type as the old plugs. Gapped .035. With new plugs, the Jeep idles and runs rough--seems like a CPM issue. Old plugs, runs fine. I didn't replace the cap or rotor. Would a hotter spark from the new plugs cause more efficent firing thus causing the CPM to regulate differently? Should I replace cap and rotor also? Thanks in advance for any help given!
CF Veteran
Joined: Oct 2009
Posts: 5,390
Likes: 3
From: Chicago IL
Year: 1997
Model: Cherokee
Engine: 4.0 Straigh 6
Greetings,
This is my first post but I have gained a wealth of information by searching here many times before--thanks to all for your generous sharing of invaluable contributions.
Here's the problem: I have a 1997 with a 4.0L which was running fine but I decided to change the wires and plugs as they had not been changed in 70000 miles. I changed the plugs, first with Autolite platinums then with Champions same type as the old plugs. Gapped .035. With new plugs, the Jeep idles and runs rough--seems like a CPM issue. Old plugs, runs fine. I didn't replace the cap or rotor. Would a hotter spark from the new plugs cause more efficent firing thus causing the CPM to regulate differently? Should I replace cap and rotor also? Thanks in advance for any help given!
This is my first post but I have gained a wealth of information by searching here many times before--thanks to all for your generous sharing of invaluable contributions.
Here's the problem: I have a 1997 with a 4.0L which was running fine but I decided to change the wires and plugs as they had not been changed in 70000 miles. I changed the plugs, first with Autolite platinums then with Champions same type as the old plugs. Gapped .035. With new plugs, the Jeep idles and runs rough--seems like a CPM issue. Old plugs, runs fine. I didn't replace the cap or rotor. Would a hotter spark from the new plugs cause more efficent firing thus causing the CPM to regulate differently? Should I replace cap and rotor also? Thanks in advance for any help given!
Thread
Thread Starter
Forum
Replies
Last Post
TREE
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
Sep 13, 2015 05:25 PM
Blue04
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
8
Sep 12, 2015 10:54 AM
2000JGC
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
Sep 11, 2015 11:45 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)



