So i had a cylinder 1 misfire due to a nls while tune engaged. Cleared that out, drove a lil then light came back on. Same deal, same cylinder. I switched coils around and checked the gaps on each plug. Plugs were fine as they were only two weeks old. Drove back to work, car sat for a few hours. Went to lunch break just riding around and light came back on again. Same problem, cylinder 1 misfire, all coils and plugs are fine. Does anyone have any input as to what the problem may be. The only thing that has changed since car was running fine was i installed a k&n sri, But have not yet had a retune. which will be done this upcoming week.

 

u check ur O2 sensor? that causes missfire as well.

 

Comp check & leakdown test is in order. I had lower comp on #3 & blowby at the fuel injector seal, took it apart and found NO teflon seal on #3 injector. Tight mechanical fit on the injector held for 50k miles before the misfires started, got so bad I couldn't get into any boost before popcorn started popping. It started in a pull with misfires at around 5k & lotsa boost.
#3 always was ~10 lbs lower on compression but I just figured the rings weren't seated well...wrong.

Seal was never there, there isn't anyplace it can go & #3 injector came out with the rail on mine, the other 3 stayed in the head with a tight fit.
I see 165-168 psi on all 4 cyls now.

Hopefully you didn't pop the ring lands.

Did you swap a plug or just the coilpacks? Move the plug if you haven't yet.

 

i visually checked the plugs but have been reading and seen that the autolite xp5263 arent good. Im a get a set of stockers tommorow and put in there then go from there. Also get retuned since i havent since the k&n sri install.

 

u know whats weird, my car completly stopped misfiring, i used to get it on idle every other start, so dashdaq said anyway, but haven had any in months

 

ive read in some places the trifecta tune will misfire when nls. But i was just everyday driving

 

mine only misfires if i dont let the temps rise to 180 before i no lift shift, and it does it like a bad habit if its not warm lol ..........pop-corn like said above

 

oh, u got autolite, lol that might be ur problem, stockers are the best i think, i had ngk one step colder, they missfired and knocked and gurggled like crazy, went back to stock, my car gave me a huge hug.

 

What's up with nls and the problems behind it lol

 

You're not supposed to use it with a tune.

 

you know what funny?

About a year ago, anybody on this forum would have probably blamed the intake based on the OP.

 

I rarely use it..........nls into 2nd is a no no if I was to use it.

 

i only nls 2-3 and 3-4, mostly just 3-4