I had a recent cold hesitation/misfire condition over the winter. So I decided to replace the igniter, coils, and spark plugs. The car has just shy of 24k miles on it, but figured that it wouldn't hurt to replace the coils and igniter, just in case. I was worried when I removed the coils, and they looked essentially brand new: no hint of corrosion. Then I removed the plugs, and I figured that this must be the cause of the misfire:
Yeah, all were covered with soot, which I'm guessing is an indication that I'm running rich. Now the car is supercharged with an AEM FIC, but an OBD2 and most of my driving is on the highway so it is mostly in closed loop and therefore the air-fuel ratio should be controlled by the 02 sensor. I did re-adjust the fuel values on the FIC since the long-term trims were around -15%. Hopefully that will fix the rich condition and the plugs will not look like that the next time I change them.
BTW, accessing those rear plugs is a complete PITA. I really hope that the longitudinal layout of the new NSX means that routine maintenance will be easier.
PS: The service manual stated to put a bit of anti-seize compound on the plugs, but the NGK website stated explicitly not to use any anti-seize since the threads on the plug are already plated to prevent seizing. So who is right?
Yeah, all were covered with soot, which I'm guessing is an indication that I'm running rich. Now the car is supercharged with an AEM FIC, but an OBD2 and most of my driving is on the highway so it is mostly in closed loop and therefore the air-fuel ratio should be controlled by the 02 sensor. I did re-adjust the fuel values on the FIC since the long-term trims were around -15%. Hopefully that will fix the rich condition and the plugs will not look like that the next time I change them.
BTW, accessing those rear plugs is a complete PITA. I really hope that the longitudinal layout of the new NSX means that routine maintenance will be easier.
PS: The service manual stated to put a bit of anti-seize compound on the plugs, but the NGK website stated explicitly not to use any anti-seize since the threads on the plug are already plated to prevent seizing. So who is right?
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