Just changed my spark plugs, and noticed a couple of things. First, when I removed the old ones, they were completely black...a thick coating of it. After putting in new plugs (9's all the way around) the idle and light load operation was noticeably smoother. But after a short while, the smoothness was gone and back the way it was.

To me, it looks like the car is running way too rich. I'm used to looking at plugs out of piston engines, so I might be mistaken. I know these rotarys need to run rich, but this looks like its too rich. There is not any noticeable smoke even under WOT. What should the plugs look like?


Gary

 

Does sound like you're running too rich. I just changed my plugs about 2k ago, and all came out gray-ish looking, which is what is considered normal wear in the manual. The old plugs had about 15K on them.

One thing I'd try is running some good quality fuel injector cleaner in the gas. That'll help clean out the carbon build up on the rotors and the housings.

Jim

 

Thanks for the info Jim. I called Peter Farrell today and asked them about the plugs. According to them, what I have is normal. Of course, maybe its normal for them because of tuning cars with extra fuel for safety. They also recommended changing the leading plugs every 5k miles and the trailing plugs every 10k miles! Seems like overkill to me, but the previous owner of my car had it tuned by them so I'll trust what they say until I know better.

 

Mine are always solid coated black except the little part where the sparks come out.... And i get lots of black smoke on WOT.
~Tom

 

bad pic of old spark plugs on the right.. with brand spankin new on the left



NGK number, TII: NGK-BUR7EQ