Hey so last week my 1999 R34 auto sedan non turbo skyline started to miss fire, I was told to replace the coilpacks and while I was in there I decided to hange my spark plugs as well ( they’re brand new splitfire coilpacks and Bosch Double platinum spark plugs) and the car is still missing, it was worse but after replacing a moly in the manifold I had forgot to put back in it’s running a little better but still has the miss, could it be a faulty coil or spark plugs or both, or could it be the coil harness?

I’m still learning a lot of things as I go and can’t figure out what could be causing the issue if you need any other info just let me know, thanks in advanceappvalley tutuapp tweakbox

 

If it's a rb26dett or rb25de non-turbo or turbo the first things first this motor should only use a ngk plugs any other plugs can cause its to act up that goes for all makes and models every vehicle has a brand spark plugs that the oem manufacturers recommend using. It's not a good idea to try anything other than what the manufacturer calls for. The car has an obd 2 scanner hooked it up get the codes go from there. I would say try ngks if thats not what's already in there and than try the coils and the injectors test to see which ones are working and which ones are not working. I see you stated something about the moly in the mannifold like to know what you did there?

 

The problem's the Bosch plugs! Use NGK or Denso! Bosch seem to work only in Germanic cars...I went thru this same crap as a kid with a modified 1974 Toyota Celica way back in the mid 80's...and again with my cousin's Pontiac Bonniville SSC! Bosch plug are always on sale for a reason... They Suck!

 

why the hell do still have a stock rb. what the hell. whaattt.sleeves, forged imternals, 6 speed swap, stroker kit, tt head, single turbo running 90 pounds of boost. lol jk. but a clean, minimalistic turbo kit would be nice.