aklano

Letting it run in the garage because I haven't driven it for a week. Exhaust is blowing a little smoke. Revved the engine a couple times and go around back and find black spray from the exhaust. Oil? Rings shot?
B 16 turbo. Will put up a pic in a second

v4lu3s

Water vapor mixed with slight soot from inside your exhaust.

aklano

I can believe that because it really didn't smell like oil and oil would burn in the cylinder anyway wouldn't it? I've just been paranoid since I came home because the car sat for four years without even being started, but I don't have any loss of low end power and it still makes boost fine. Only thing I've noticed is black smoke coming from the exhaust when I'm on boost. What might cause that?

Atomic1

That was happening on my b16 when my primary o2 sensor was dying and running the engine rich. When you run rich, you get black deposits throughout the exhaust...then on startup, when it spits out water vapor, it pulls the black crud with it....

v4lu3s

im curious, what is the car tuned with? possible that fuel trims are slightly off? how much has it been driven since it sat for four years?

slowcivic2k

This is common on a lot of vehicles with a rich A/F. I've tailpiped a lot of large engine vehicles and most will produce a lot of water vapor without the soot-spitting.

There are a lot of fuel related issues that can cause this. Fuel pressure, injector on-time (pulse width), ignition timing, and in a few cases converter efficiency. If you do not use a converter, this problem will be more prominent as the converter is not present to re-combust fuel that didn't do so the first time around in the engine.

I would start with finding all discrepancies with your vehicle. Different ECU? Different injectors? Different Regulator? Aftermarket fuel control? Poor tuning?

A lot of aftermarket turbo vehicles will use more fuel to prevent excessive combustion chamber temperatures. In these cases, it can be considered "acceptable".

aklano

Car is tuned on Hondata. It runs very rich.

slowcivic2k

A rich tune is characteristic of an incomplete tune. Turbo vehicles may always require some extra fuel to prevent unwanted knock, but this is almost always due to a tune that cannot take into consideration the enormity of operating conditions a vehicle may experience. The few tunes I have witnessed are incomplete 40-50% throttle tunes, and a full lead tune. The remaining 80% of the time you are at the mercy of whatever values were plugged in. Some engines may not idle with larger injectors and will also require an idle tune as well. Tuning correctly takes a lot of time and may or may not be worth your added money and effort. It is very unfortunate, but reprogramming all the variables for fuel management is not as easy as some tuners may make it seem like it is.

aklano

Thanks for your input slow.