Jeep Stroker 4.7L

[Drv2e30]

Current Setup
-258 Crank and Rods - with Hesco Spacer
-Sealed Power Bearings and ARP Studs
-1990 Wrangler 4.0l engine
-Bored out .04 with new dished pistons
-High Flow Head, Ported and polished, oversized stainless valves
-Crane Cam
-2000 Intake manifold and electronics
-24lbs Reman Ford Injectors
-Header that works with the stock 2000 cats
-New O2 Sensors (upper and lower)
-Stock ECU
-Stock Coil Rail - (going to upgrade to SilverXJ's setup in a little bit)
-Fresh Build from Machine shop

I just finished the 1700 miles after I got it first installed. Initially it was working great but in the last 300 miles it started to have issues and threw misfire codes. For the break-in I had used Champion Plugs RC12ECC at a stock gap of .035. I think it started to throw codes after the rings seated. I just switched to the NGK ZFR6F-11 with a gap of .044 (I had to gap the plugs again when I got them, they came as .040) and reset the OBDII. I just ran the truck for a day and it just threw a code (haven't read it yet). Any ideas on what the issue could be?

Here are the images from the Champion plugs:
(Top plug is the cylinder by the firewall)

(Far right plug is the cylinder by the firewall)

[Cheromaniac]

-Stock Coil Rail - (going to upgrade to SilverXJ's setup in a little bit)
I just ran the truck for a day and it just threw a code (haven't read it yet). Any ideas on what the issue could be?

If you get a misfire code on the no.6 cylinder, the reason could be a faulty coil or faulty plug wire.

[SilverXJ]

That # 6 plug looks pretty bad, especially with that low miles.

[Drv2e30]

Should I consider replacing the coil rail or just trying another set of plugs?

Also, I just remembered that the 6th plug was actually borrowed from an older motor since I broke the newer plug I bought for that cylinder. So it looks a little worse for that reason.

[Cheromaniac]

Also, I just remembered that the 6th plug was actually borrowed from an older motor since I broke the newer plug I bought for that cylinder. So it looks a little worse for that reason.

Mmmm. You could have mentioned that little detail in your first post.
Just replace that plug with a new one and see if you still have a misfire.

[Drv2e30]

My apologies, here is some additional information for you:

ORIGINAL CHAMPION PLUGS (Shown in Photos) - [RC12ECC at a stock gap of .03]
-I had these plugs in the engine from when I first put it in after receiving it from the machine shop
-I about 1400 Miles in I started to get Misfires on cylinders 1 and 3

New plugs installed at 1700 miles with the new engine.
-NGK ZFR6F-11 with a gap of .044 (I had to gap the plugs again when I got them, they came as .040) and reset the OBDII
-After about 300 miles I got a misfire again on cylinder 3
-I plan on pulling the 3rd plug this weekend to check what it looks like.

I think this may be due to the fact that my coil rail is currently held in with zip ties. I think I'm going to do SilverXJ's viper pack upgrade to reduce the possibility of the plug not getting the spark it needs when the road gets bumpy.

[Cheromaniac]

I think this may be due to the fact that my coil rail is currently held in with zip ties. I think I'm going to do SilverXJ's viper pack upgrade to reduce the possibility of the plug not getting the spark it needs when the road gets bumpy.

Sounds like a good eye deer.

[Drv2e30]

So it has been a while, but I fabbed up some mounts for the coil rail and it appears to be holding in place well now.

Though I'm still having a misfire and still can't figure out the issue.

One friend recommended changing the fuel pressure regulator for an adjustable one but apparently with the 2000 XJ's I don't have an option to do that. Should I just revert back to my older stock injectors?