smoking at idle

[minytrker]

I just got my z06 back together after getting the heads done. My car is smoking a little at idle, which is from fuel. I have a large cam without cars and have the a/f at 14.6 at idle. The car idles and drives perfect. Is the car just to rich at idle? What could be causing the smoke?

[kbracing96]

What color is the smoke? If it's black, then it's to rich, but it won't be running smoothly at all if its rich enough to smoke. If its blue, then its most likely oil, and if you just did the heads, I'd guess that somebody didn't install correctly or damaged the valve seals.

[minytrker]

Its black smoke and it smells like its from fuel. I know a wideband isnt very accurate at idle with a large cam so Im guessing its rich even though though wideband isnt reading rich. Im going to lean it out today and see. It is idling perfect just smoking a little,lol.

[minytrker]

Well after driving around today, its more of a white smoke. I got oil in my pcv system the other day, so it may just be buring that off. Also since I just the heads done it could be valve seals. I called the shop who did the heads and they to drive for a few days then if it still does it to put teflon on the rocker arm bolts.

[Bruce Melton]

The sealer in the rocker bolts makes more difference than you would ever imagine. Did for me anyway.

[VetPet]

Without cats on the car the smell would make you think it's running rich. Smells pretty strong and there's really no reason not to run without cats if you put a set of the hi-flo's on like random tech or bassani. The newer metal substrate cats have more flow capability than a lot of the mufflers in the market so you're not going to give up performance. A wide band O2 sensor will work with whatever cam you have. It's only measuring the amount of air in the mixture and doesn't know what kind of cam you have in the car. Glad to see that you got your smoke problem resolved.

:cheers:

[minytrker]

Without cats on the car the smell would make you think it's running rich. Smells pretty strong and there's really no reason not to run without cats if you put a set of the hi-flo's on like random tech or bassani. The newer metal substrate cats have more flow capability than a lot of the mufflers in the market so you're not going to give up performance. A wide band O2 sensor will work with whatever cam you have. It's only measuring the amount of air in the mixture and doesn't know what kind of cam you have in the car. Glad to see that you got your smoke problem resolved.

:cheers:

I dont have cats because I didnt want to blow $300 more on them. The reason I said that about my wideband is because how far back it is, same thing with my front o2s. They are both far enough back with my LG heads that they arent getting enough hot air or air flow at idle to be all the way correct. I had to do some tweaking in my OS at the idle so the car would quit trying to correct off the o2 readings. I have only ran into this with the LG Pro headers. Hope this makes sense.