missing on one cylinder
long story short, I replaced everything a/c related under the hood. in doing so, I broke the o-ring on the radiator plug so that when it was ran, lost all antifreeze and overheated. When it overheated, I dropped a valve seat. ended up replacing entire engine with a rebuilt one. now since replacing the engine I get a missfire on cylinder one. only cylinder one. I have replaced cam shaft sensor, crankshaft sensor, new spark plugs, new coils, new injector, the only things not new on this engine are the intake and throttle, and map sensor. swapped everything between cylinders, miss stayed on number one. noid light was flashing in injector connector but seemed weak. so used multi meter to check voltage and was less than 1 volt with key on but not started. replaced ecm as the last resort. went from having a solid cel to having just a pending p0301. but I can still feel it's missing. I think I have done everything the other posts here have suggested with no results, any insights would be greatly appreciated.
2008 nitro sxt