2002 Infiniti QX4 P0300 -> P0304

[theomajigga]

Hello all,

I recently bought a QX4 for a good deal and I'm starting to see why :/ I'd like to keep the vehicle so I have started to do some troubleshooting.

Things started with a P0300, P0051, P0057. Got the car home, and started by clearing the codes. Started it up and the code came back quickly.

Removed coil connectors until I got the #4 which didn't change the current misfire. Pulled the intake hose to test the coil out, it tested within what the other were at (I might have more than one bad). Swapped #4 with #2, just in case it was moved to #2 but it didn't do that. When in there I noticed that they had stripped some insulation off of the #4 signal wire and had it either going to ground or who knows, as it was just wrapped around it and loose. Super f'n pissed at this point, but the fight goes on.

After I swapped the coils, it went to a hard P0304, still smells like fuel, but so far no 51 or 57 (haven't driven it to far). I pulled the trim to get to the ECM just to check signal continuity and it was good, but they were in there too as the ECM was also loose. Oh well.

What I'm going to do:

1. Change the plugs

And then I'm out of ideas, since the coil swap didn't seem to do much. Could it be the injector?

Youtube of the idle and a ramp up to RL. It has a weird stutter around 1700 - 3700, can't get it to go in-between.

https://www.youtube.com/watch?v=33yc_EBwb7c

[theomajigga]

Found my issue: The conductor that is in the center of the coil boot was missing.

[barnaclebob]

Thanks for posting the solution.