The injectors and rail are typically not replaced as maintainance items, only when not functioning properly. I replaced the heat shield on mine when I replaced the valve cover gasket but only because I like having a clean engine.
Injector Rail Maintenance-Replacement 2004 - 4.0 - 150K
Hi Gang (Hope We're All Doing Ok)? 
Photos of 2004 - After 150K wondering if replacement of Rail, Injectors (and) Shield are necessary?
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THANK YOU
Photos of 2004 - After 150K wondering if replacement of Rail, Injectors (and) Shield are necessary?
THANK YOU
1 - 4 of 4 Posts
"I replaced the heat shield on mine "
Hi WolfeJeep - (thanx for the reply) Unfortunately the shop that replaced the Valve Cover did not mention the Heat Shields? My fault for not following up. I can tell you that; (after running the AC on a 50-80 mile drive), it starts to run a little rough. Could you tell me how difficult it is to replace the Heat Shields? Does it require dismantling the rail and pulling out the injectors?
Thank You!
Hi WolfeJeep - (thanx for the reply) Unfortunately the shop that replaced the Valve Cover did not mention the Heat Shields? My fault for not following up. I can tell you that; (after running the AC on a 50-80 mile drive), it starts to run a little rough. Could you tell me how difficult it is to replace the Heat Shields? Does it require dismantling the rail and pulling out the injectors?
Thank You!
"I replaced the heat shield on mine "
Hi there Mr. WolfeJeep - unfortunately the shop that replaced the Valve Cover did not even mention the Shields should also be replaced and my fault for not following through. I can tell you that (after running the AC on a 50-80 mile drive), it starts to run a little rough. By turning off the AC it seems to settle down. Back to the Shield Replacement: Can you tell me how difficult that is? Does it require dismantling the rail and pulling out the injectors?
Thank You!
It only required disconnecting the intake air temp sensor electrical connector, the intake air tube at both ends, the throttle cable from the throttle body and removing the throttle cable bracket from the intake manifold (if I remember correctly). The shield itself is just slipped over two of the head bolt studs and is not really bolted to anything. Take a look at it, it's pretty simple. I'm 2500 miles from my TJ right now so I can't take a look."I replaced the heat shield on mine "
Hi there Mr. WolfeJeep - unfortunately the shop that replaced the Valve Cover did not even mention the Shields should also be replaced and my fault for not following through. I can tell you that (after running the AC on a 50-80 mile drive), it starts to run a little rough. By turning off the AC it seems to settle down. Back to the Shield Replacement: Can you tell me how difficult that is? Does it require dismantling the rail and pulling out the injectors?
Thank You!
1 - 4 of 4 Posts
