I have an 03 disco that I just replaced the fuel injector on. After everything was buttoned up it fired up just fine but once it started to warm up the SES light started flashing and the idle became rough and the rig was barely able to stay running. Once you get it moving the SES light stops flashing and it drives like there is nothing at all wrong with it. I was able to get it to o'Reilly's and plug in the code reader and it gave me misfire codes on 1 4 & 6. Plugs are 6 months old and wires are new. There were no misfire codes present before installing the new fuel injectors. I triple checked all the connections when buttoning everything back up. Any ideas?

 

How old are the coilpacks?

 

To be honest I couldn't tell you. I'm not the first owner and I haven't replaced them since I've had the vehicle so I'm just going to assume they are original?? I'm at 180,000 ish miles on this vehicle. Its just weird to me that it was running without misfires before the injector swap abs then all of a sudden I have 3 cylinders misfiring. I never undid the spark plug leads on the coil pack when I did the injectors. So I tore into it again last night to replace the plug wires and the problem is still there. I have ordered a new coil pack and will replace it regardless, but something is telling me it's not the issue.

 

If you take the upper intake off to check the injectors, I suppose it is possible they are not seated perfectly, put in new Coilpacks. I put in Standard Motor Products and they have been fine, but I am going with Bosch sensors from here on out.

 

I went ahead and ordered them. Should be here on Thursday. I'll swap them out and report back. If anyone can think of another area of suspect, I'm listening. Thank you!!

 

I hope that takes care of it.

 

Thanks! You dont think the new fuel injectors are somehow related to the sudden misfire do you? I cant think of how they would be but that's the only thing that was done to the rig between it not having misfires and having misfires.

 

I doubt it. Maybe re-torque the spark plugs?

 

One way to test for bad injectors is to swap injectors (to use yours as an example, swap 1 and 3, 2 and 4, and 6 and 8) and see if the code follows the injectors (giving you misfire codes on 2, 3, 8).

 

I'll go ahead and try those. At least I can be proactive and rule some things out while I wait for the new coils. Thanks guys.