[Dannikb]

Help
I have misfire issue, I've changed distributor, the cap & rotor, knocking sensor, spark plugs & wires, timing belt d and still does the same thing...what could it be??

 

[MeToo]

Step One: Get the codes scanned, all 4 groups: B, C, P, and U.

"Changed" the dizzy. Did you replace it or just overhaul it? If it's a new dizzy, is it either Hitachi (OE mfr) or Nissan? If not, there are reported issues with off-brand dizzies.

What octane fuel are you burning, and what brand? Is it listed as a Top Tier Fuel? https://www.toptiergas.com/fuel-stations/

 

[Blackberry]

Besides the things you mentioned, I’ve seen:

clogged fuel filter
Fuel sending unit corrosion
Blown out supercharger gasket(this should have been replaced when the knocking sensor was replaced)
Supercharger bypass valve leak
Injectors
Clogged converters
Fuel pressure regulator
Water in fuel

 

[Satito]

Don't forget vacuum leak.

 

[ajechase74]

How random is the random? I had a "random" #4 misfire. Same spot in the block as your #3. Then paying very close attention to it, I waited it out. Engine ran fine cold but misfire would occur soon after the thermostat opened. Voila, the dreaded head gasket leak. As my issue was fairly new and I have almost 173K on my X, I turned to a bottle of Bar's Leaks Block Seal Head Gasket Fix. I didn't have abnormal coolant loss, oil in the coolant, foamy oil, none of that. So I would check on that and do a compression test while you're at it.

NO!! This is not my preferred fix, but it is getting me by as I am currently unemployed and my Ram Diesel truck is waiting in the shop "3-6 weeks" for a high pressure fuel pump replacement that isn't the current recall fix. But for now I can still try to find work and get my kid to school.

 

[Blackberry]

This is why the service manual calls the P0300 “Multiple cylinder misfire” and not “Random cylinder misfire”. There’s usually nothing random about it