My 99 cav Z24 just started to rough idle today but no engine light, Just put in new plugs and the boots and housing are fine I checked them out. what can cause this and how can I fix it? car only has a 100,000 kms on it.
You may have encountered a bad plug, even though new....
This often happens, with almost all brands of plugs....
Answer - pull the plugs, look for any that are dark in color....
If dark, they're not firing properly....
Could be an injector, pcm, coil packs, crazy fuel pump(pressre). Quite a few people have this problem, including me.