DarkRed86Z

I had a miss develop suddenly one day while driving around. Grounding one plug wire at a time, I narrowed it to #4. I knew it was about time for attention to the ignition system, so I replaced plugs, rotor, cap, wires, along with the O2 sensor for good measure. The old plugs showed heavy black soot on #4, along with lesser soot on #2 and #6. #1, #3, and #5 looked normal. This made me think uh..oh, it might be something besides ignition. ECCS Diagnostics reported no codes. I drove the car about 5 miles with the new ignition parts installed, and it ran great. But when I started it up 30 minutes later, the miss was back. I drove it home and removed plug #4 to find heavy block soot fouling. Some soot had accumulated on #2 as well. A compression check on #4 was 160 psi, and 170 psi on #2. i didn't bother to pull #6.


My best guess is that I have a badly leaking injector on #4. The injector recall was done on this car in 2006, parts records indicate 16603-01P27 Injector and tube among other things. Are there any known issues with the recall injectors Nissan installed? I never had any issues with the original injectors; just had it done to get new injectors for free. Any known bad effects on injectors from e10 gasoline?

What do you guys think? Am I on the right track? Anything else I can check? if it is an injector, what is the best way to proceed, new, send to injector shop, upgrade to other injectors, or what?

Plugs as removed. These don't have many miles on them, but I replaced them anyway since I was replacing wires, cap, rotor, etc. Note #4.



Brand new Denso #3008 plugs from cylinder #4 (right), and cylinder #2 (left) after about 15 miles.

hoov100

First things first, clean those plugs and set the plug gaps, then inspect the plug wires if the plug wires check out ok, replace #4 with a known good one, if that checks out, inspect the cap and rotor for wear and note if there is no wear on the #4 contacts. Come back to us and tell us what you find.

DarkRed86Z

I am 99 and 44/100% sure it's not ignition. I thought it was at first, and replaced cap, rotor, wires, plugs, o2 sensor. Problem happened again with new plugs. Same appearance.

It is soft, black, sooty carbon fouling consistent with rich mixture. It's not wet black oil fouling, and oil consumption is nil. 2,4,and 6 are all in one injector group since the recall was done. All show carbon fouling, although #4 is worst. I wonder if that ties in somehow; but the recall was done back in 2006.